Introduction

The order Tubeufiales was introduced by Boonmee et al. (2014) to accommodate the type family, Tubeufiaceae, based on molecular phylogenetic studies. In the same year, Suetrong et al. (2014) introduced a second family Wiesneriomycetaceae to Tubeufiales based on morphological and DNA sequence data. Bezerra et al. (2017) excluded Wiesneriomycetaceae from Tubeufiales based on phylogenetic analysis. However, the latest studies on divergence times estimates treated Bezerromycetaceae and Wiesneriomycetaceae as families of Tubeufiales (Liu et al. 2017), which we follow here.

Tubeufiaceae was established by Barr (1979) based on the generic type Tubeufia. Within the last decade, a number of studies on tubeufiaceous taxa have been published (Boonmee et al. 2011, 2014; Rajeshkumar and Sharma 2013; Hyde et al. 2016a, 2017; Brahamanage et al. 2017; Chaiwan et al. 2017; Dai et al. 2017; Doilom et al. 2017; Jayasiri et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Goh and Kuo 2018; Kuo and Goh 2018a, b; Liu et al. 2018; Phookamsak et al. 2018; Rajeshkumar et al. 2018). To date, the family Tubeufiaceae includes 26 genera: Acanthohelicospora, Acanthophiobolus, Acanthostigma, Acanthostigmina, Aquaphila, Boerlagiomyces, Bifrontia, Chlamydotubeufia, Dictyospora, Helicangiospora, Helicoma, Helicomyces, Helicosporium, Helicotubeufia, Kamalomyces, Manoharachariella, Muripulchra, Neoacanthostigma, Neohelicomyces, Neohelicosporium, Neotubeufia, Podonectria, Tamhinispora, Thaxteriella, Thaxteriellopsis and Tubeufia (Link 1809; Nees 1817; Corda 1837; de Notaris 1863; Norman 1872; Berlese 1893a; Penzig and Saccardo 1897; Höhnel 1909; Petch 1921; Petrak 1924; Sivanesan et al. 1976; Butzin 1977; Goh et al. 1998; Boonmee et al. 2011, 2014; Rajeshkumar and Sharma 2013; Brahamanage et al. 2017; Chaiwan et al. 2017; Doilom et al. 2017; Luo et al. 2017; Liu et al. 2018; Lu et al. 2018; Phookamsak et al. 2018; Wijayawardene et al. 2017a, b, 2018). Tubeufiaceous taxa are widespread in tropical and temperate regions (Boonmee et al. 2011, 2014; Brahamanage et al. 2017; Doilom et al. 2017; Luo et al. 2017; Phookamsak et al. 2018). Most species in this family are saprobic on terrestrial woody substrates and some are from aquatic habitats (Barr 1979, 1980; Rossman 1987; Kirk et al. 2001; Ho et al. 2002; Cai et al. 2003; Zhao et al. 2007; Boonmee et al. 2011, 2014; Hyde et al. 2016a; Brahamanage et al. 2017; Chaiwan et al. 2017; Doilom et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Liu et al. 2018; Phookamsak et al. 2018). The sexual morphs of Tubeufiaceae are characterized by superficial ascomata, a pseudoparaphysate hamathecium, bitunicate asci, and many septate, hyaline to pale brown cylindrical ascospores (Barr 1979, 1980; Rossman 1987; Kirk et al. 2001; Boonmee et al. 2011, 2014; Brahamanage et al. 2017; Chaiwan et al. 2017; Dai et al. 2017; Hyde et al. 2017; Jayasiri et al. 2017; Lu et al. 2017a, b, c; Liu et al. 2018; Phookamsak et al. 2018). The asexual morphs of Tubeufiaceae are hyphomycetous, mostly helicosporous, some are chlamydosporous and phragmosporous (Tsui and Berbee 2006; Tsui et al. 2006, 2007; Boonmee et al. 2011, 2014; Rajeshkumar and Sharma 2013; Hyde et al. 2016a, 2017; Brahamanage et al. 2017; Chaiwan et al. 2017; Doilom et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Wijayawardene et al. 2017a, b; Kuo and Goh 2018a, b; Liu et al. 2018; Rajeshkumar et al. 2018).

Tubeufiaceous taxa, especially the helicosporous members, have the potential to produce a number of bioactive compounds. Itazaki et al. (1990) obtained two new cyclotetrapeptides (Fig. 1, compounds 1–2) from Helicoma ambiens RF-1023, and found that these two compounds exhibited detransformation activity against ν-sis oncogene-transformed NIH3T3 cells. Hanada et al. (1996) reported a novel protein produced by a species of Helicosporium, which had effects on neurite outgrowth via cultured cortical neurons and NGF-treated PC12 cells. Ohtsu et al. (2003) characterised five compounds (Fig. 1, compounds 3–7) from Helicomyces sp. No. 19353, and found that compound 3 had a significant anti-diabetic activity (Ohtsu et al. 2003; Yoshimura et al. 2003; Zenkoh et al. 2003). Dong et al. (2004) reported that 98.95% mobility of nematodes were inhibited by mycelial extracts from Helicomyces roseus. Jiao et al. (2006) reported that seven compounds (Fig. 1, compounds 8–14) were isolated from Tubeufiaceae sp. A-00471. Compounds 8 and 10–13 exhibited antibiotic activity against Gram-positive bacteria (Jiao et al. 2006). Hu et al. (2006) obtained six compounds (Fig. 1, compounds 15–21) from Helicoma viridis. Compounds 15–18 were active against Pseudomonas aeruginosa and compound 16 displayed activity against Lactococcus lacti (Hu et al. 2006). Jung et al. (2012) reported that 2-methylresorcinol (Fig. 1, compound 22) from Helicosporium sp. KCTC 0635BP exhibited antimicrobial activity against various types of bacteria and fungi, and also exhibited considerable cytotoxicity against mammalian cells. Lee et al. (2013) found that Helicosporium sp. 0635BP was effective against Rhizoctonia solani, Fusarium oxysporium and Phytophthora drechsleri, which is indicative of a promising biocontrol agent on turfgrass large patch disease.

Fig. 1
figure 1

Compounds isolated from Tubeufiaceae spp. Compounds 1–2, isolated from Helicoma ambiens RF-1023. Compounds 3–7, isolated from Helicomyces sp. No. 19353. Compounds 8–14, isolated from Tubeufiaceae sp. A-00471. Compounds 15–21, isolated from Helicoma viridis (Strain No. 2203). Compound 22, isolated from Helicosporium sp. KCTC 0635BP

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Helicosporous hyphomycetes are a morphologically fascinating group of microfungi. In the family Tubeufiaceae, helicosporous asexual morphs are represented in several genera, viz. Acanthohelicosporium, Chlamydotubeufia, Helicangiospora, Helicoma, Helicomyces, Helicosporium, Helicotubeufia, Neocanthostigma, Neohelicomyces, Neohelicosporium and Tubeufia (Kodsueb et al. 2006; Tsui and Berbee 2006; Tsui et al. 2006, 2007; Boonmee et al. 2011, 2014; Hyde et al. 2016a; Brahamanage et al. 2017; Chaiwan et al. 2017; Doilom et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Liu et al. 2018). Their general morphologies are characterized by partly superficial colonies on decaying woody substrates, macronematous conidiophores, holoblastic, monoblastic and/or polyblastic conidiogenous cells, and helicoid, septate, hyaline to variously coloured, smooth-walled conidia with varying number of conidial coils (Kodsueb et al. 2006; Tsui and Berbee 2006; Tsui et al. 2006, 2007; Boonmee et al. 2011, 2014; Hyde et al. 2016a; Brahamanage et al. 2017; Chaiwan et al. 2017; Doilom et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Liu et al. 2018).

Helicosporous hyphomycetes are still a confused taxonomic group. Some species have been transferred several times. For example, Moore (1957) treated Drepanospora pannosa as Helicosporium pannosum; Matsushima (1975) introduced four new records of H. pannosum and synonymized Drepanospora pannosa, Helicosporium linderi, Helicosporium nematosporum and Helicosporium serpentinum under Helicosporium pannosum; Goos (1989) treated all as Drepanospora pannosum; Zhao et al. (2007) treated all and Helicosporium gigasporum as Helicosporium pannosum. In fact, there are many similar examples within the helicosporous members of Tubeufiaceae where taxonomy has been revisited (Linder 1929, 1931; Moore 1957; Matsushima 1975, 1985; Goos 1985, 1986, 1989; Zhao et al. 2007; Boonmee et al. 2014).

Another major taxonomic problem is that many species which have been morphologically identified to the genus have been shown to belong to different clades in either single gene or multi-gene phylogenetic trees (Tsui et al. 2006, 2007; Tsui and Berbee 2006; Boonmee et al. 2011, 2014; Luo et al. 2017). For example, Tsui et al. (2006) provided the ITS and LSU sequence data for Helicosporium linderi (NBRC 9207) and Helicoma vaccinii (CBS 216.90), however, their phylogenetic analyses showed that Helicosporium linderi nested among Helicoma species with good bootstrap support while Helicoma vaccinii grouped within Helicosporium species. Tsui and Berbee (2006) analysed the LSU and SSU sequence data for Helicoma isiola (UAMH 1359), but phylogeny indicated that H. isiola did not belong to Helicoma and did not even group within Tubeufiaceae. Boonmee et al. (2014) reported Helicosporium indicum (CBS 374.93) and Helicoma talbotii (MUCL 33010) within Helicomyces. Luo et al. (2017) found that two isolates of Tubeufia helicomyces (CBS 245.49 and CBS 271.52) clustered within Neohelicomyces. These previous studies revealed that misidentifications in Tubeufiaceae may exist at both species and generic level.

Furthermore, our previous studies reported that morphologically similar helicosporous groups can be distinguished based on DNA sequence phylogenetic analyses (Lu et al. 2017c, 2018; Luo et al. 2017). For example, Lu et al. (2017c) reported that four dematiaceous helicosporous hyphomycetes species were morphologically similar, but phylogenetically distinct. Luo et al. (2017) introduced three morphologically similar helicosporous taxa that were phylogenetically distinct species. Lu et al. (2018) provided more evidence on morphologically similar helicosporous taxa that can be distinguished by molecular phylogenetic analyses.

Accordingly, we considered that many helicosporous species might be wrongly named, even at the genus level. Therefore, the aims of this study are: (1) to reappraise and revise the placements of genera in Tubeufiales based on multi-gene phylogenetic analyses and morphology; (2) to provide details on morphological characteristics of helicosporous species of Tubeufiales; (3) to update the taxonomy of earliest described helicosporous group, viz. Helicoma, Helicomyces and Helicosporium; and (4) to provide an updated backbone tree for Tubeufiales.

In this study, 118 fresh collections of tubeufiaceous taxa are reported from aquatic and terrestrial habitats in southern China and Thailand. Thirteen new genera, 52 new species, 43 new combinations and 16 new records are introduced. The genus Chaetosphaerulina is referred to Dothideomycetes genera incertae sedis, and Artocarpomyces and Helicodochium to Ascomycetes genera incertae sedis, but accepted in the family Tubeufiaceae. Neorhamphoria is transferred to the family Bezerromycetaceae. The taxonomy of Helicoma, Helicomyces, Helicosporium are reviewed and redefined. An updated phylogeny based on ITS, LSU, RPB2 and TEF1α sequences of the Tubeufiales is provided. The checklist of accepted Tubeufiales species and re-organised Tubeufiales species are also provided. The distribution of accepted tubeufiaceous taxa are listed as known distribution and possible distribution, which referring to the records was identified based on only morphology and lack molecular evidence (The superscript ▲ within possible distribution referring to this record is supported by molecular data).

Materials and methods

Sample collection and specimen examination

Decaying wood were collected randomly from different sites in southern China and Thailand following procedures described previously (Boonmee et al. 2014; Hyde et al. 2016b). Micromorphological structures were photographed using a Nikon ECLIPSE 80i compound microscope fitted with a Canon EOS 600D digital camera and measurements were made using Tarosoft (R) Image Frame Work program. Figures were processed with Adobe Photoshop CS6 Extended version 10.0 software (Adobe Systems, USA).

Single spore isolations were obtained using the method described by Chomnunti et al. (2014). Germinating spores were aseptically transferred to fresh potato dextrose agar (PDA) or malt extract agar (MEA) plates and incubated at 25–30 °C as outlined by Vijaykrishna et al. (2004). Cultures were grown for 1–2 months and morphological characters, such as colour, colony shape, and texture were recorded. Type materials are deposited in the Herbarium of Mae Fah Luang University (Herb. MFLU), Chiang Rai, Thailand, Herbarium of Cryptogams Kunming Institute of Botany Academia Sinica (Herb. HKAS), Kunming, China and the Guizhou Academy of Agricultural Sciences (Herb. GZAAS), Guiyang, China. Ex-type living cultures are deposited at Mae Fah Luang University Culture Collection (MFLUCC), Thailand Bioresource Research Center (TBRC) and Guizhou Culture Collection (GZCC). Facesoffungi and Index Fungorum numbers are provided (Jayasiri et al. 2015). New taxa are established based on recommendations outlined by Jeewon and Hyde (2016).

DNA extraction, PCR amplification and sequencing

Genomic DNA was extracted from fungal mycelium grown on PDA or MEA at 28 °C for 30 days (Jeewon et al. 2002). Four gene regions were amplified with universal primers, namely the internal transcribed spacer regions of ribosomal DNA (ITS: ITS5/ITS4) (White et al. 1990), large subunit nuclear ribosomal DNA (LSU: LROR/LR5) (Vilgalys and Hester 1990), RNA polymerase II second largest subunit (RPB2: fRPB2-5F/fRPB2-7cR) (Liu et al. 1999), and the translation elongation factor 1-alpha gene (TEF1α: EF1-983F/EF1-2218R) (Rehner and Buckley 2005). The ITS, LSU and TEF1α amplification reactions were carried out using the method described by Cai et al. (2005) and Lu et al. (2017b). The RPB2 amplification reactions were carried out using the method described by Lu et al. (2018). The PCR products were purified and sequenced with the same primers at Sangon Biotech, Shanghai, China.

Phylogenetic analysis

Sequences generated from different primers were analyzed with other sequences obtained from GenBank. Appropriate sequences were selected by using a BLAST search to find similar matches with taxa in Tubeufiales and those in recent relevant publications (Tsui et al. 2006, 2007; Boonmee et al. 2011, 2014; Hyde et al. 2016a, 2017; Brahamanage et al. 2017; Chaiwan et al. 2017; Doilom et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Goh and Kuo 2018; Kuo and Goh 2018a, b; Liu et al. 2018; Phookamsak et al. 2018). Botryosphaeria agaves and B. dothidea (Botryosphaeriaceae) were selected as the outgroup taxa. The sequences are deposited in GenBank and the accession numbers in the analyses are provided in Supplementary Table 1. The sequence data were aligned using MAFFT v.7.110 online program (http://mafft.cbrc.jp/alignment/server/) (Katoh and Standley 2013) and manually adjusted via BioEdit 7.2.3 (Hall 1999). The alignment was deposited in TreeBASE (http://www.treebase.org, submission number 23009).

“ALTER” (Glez-Peña et al. 2010) was used to format the aligned fasta file for RAxML analysis. Maximum likelihood (ML) analysis was performed at the CIPRES Science Gateway v.3.3 (http://www.phylo.org/portal2/; Miller et al. 2010) using RAxML v.8.2.10 as part of the “RAxML-HPC2 on XSEDE” tool (Stamatakis et al. 2008; Stamatakis 2014). All free model parameters were estimated by RAxML with ML estimates of 25 per site rate categories. The final ML search was conducted using the GTRGAMMA + I model. The best scoring tree was selected with a final likelihood value of − 62352.942071. RAxML bootstrap support values greater than 75% are given at each clade (Fig. 2).

Fig. 2
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Phylogram generated from maximum likelihood analysis based on combined ITS, LSU, RPB2 and TEF1α sequence data for species of Tubeufiaceae. RAxML bootstrap support values equal to or greater than 75% are given before the forward slash. Branches with bayesian posterior probabilities equal to or higher than 0.95 are given after the forward slash. Hyphen (‘-’) indicates a value lower than 75% for RAxML and a posterior probability lower than 0.95 for Bayesian. Newly generated sequences are in bold. Strains isolated from the holotype, epitype, paratype and reference specimens are indicated in with a red superscript H, E, P and R, respectively

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Phylogenetic analyses were performed by using PAUP v.4.0b10 (Swofford 2002) for maximum parsimony (MP) and MrBayes v.3.2.2 (Ronquist et al. 2012) for Bayesian analyses. MP analyses were performed using the heuristic search option with 1000 random taxa addition and tree bisection and reconnection (TBR) as the branch-swapping algorithm. All characters were unordered and of equal weight, and gaps were treated as missing data. Maxtrees were unlimited, branches of zero length were collapsed and all multiple, equally parsimonious trees were saved. Clade stability was assessed using a bootstrap (BT) analysis with 1000 replicates, each with ten replicates of random stepwise addition of taxa (Hillis and Bull 1993). The best-fit model of sequences evolution was estimated via MrModeltest 2.2 (Nylander 2004). Markov Chain Monte Carlo sampling (MCMC) in MrBayes v.3.2.2 (Ronquist et al. 2012) was used to determine the posterior probabilities (PP) (Rannala and Yang 1996; Zhaxybayeva and Gogarten 2002). Phylogenetic trees were sampled every 100th generation (resulting in 100,000 total trees) in 10,000,000 generations from the running of six simultaneous Markov chains. The first 20,000 trees, which contained the burn-in phase of the analysis were discarded. The remaining 80,000 trees were used to calculate the posterior probabilities (PP) in the majority rule consensus tree (Liu et al. 2011). Bayesian posterior probabilities equal or greater than 0.95 are given at each node (Fig. 2). Phylogenetic trees were visualized using FigTree v1.4.0 (http://tree.bio.ed.ac.uk/software/figtree/, Rambaut 2012).

Results

Phylogenetic analysis of combined ITS, LSU, RPB2, TEF1α sequence data

The combined aligned sequence matrix comprises ITS (809 bp), LSU (844 bp), RPB2 (1051 bp) and TEF1α (913 bp) sequence data for 322 taxa with a total of 3617 characters, of which 2009 characters were constant, 256 variable characters were parsimony-uninformative and 1352 characters were parsimony informative. RAxML and Bayesian analysis of the combined dataset resulted in phylogenetic reconstructions with largely similar topologies, and the RAxML tree is shown in Fig. 2.

One of the main problems of resolving species in Tubeufiaceae is that many of the sequenced collections of species are not from the type and were not illustrated so it is impossible to verify their identities. Thus, for the time being we must treat the phylogenies of the putatively named taxa with caution and not assume they are correct. For example, many taxa sequenced by Tsui et al. (2006, 2007) were loaned from CBS and none of the taxa can be verified. It is therefore essential that all species without type sequence data are recollected and epitypified (Ariyawansa et al. 2014) to resolve the placement of these taxa.

Clade 1 (80 taxa) represents the genus Tubeufia which is the type genus of Tubeufiaceae, including 46 new taxa and three misidentified taxa, viz. Helicoma perelegans (ATCC 22621), Helicoma sp. (BCC 3512) (Tsui et al. 2006) and Helicomyces roseus (BCC 3381) (Kodsueb et al. 2006). The authors provided their molecular data but did not describe the morphological characteristics, and hence we renamed these three taxa as Tubeufia sp., Helicomyces geniculatus (BCRC FU30849 and NCYU U2-1B) (Kuo and Goh 2018b) and H. lilliputeus (NBRC 32664) (Tsui et al. 2006) are synonymized under Tubeufia.

Clade 2 (11 taxa) represents the new genus Pseudohelicomyces. Boonmee et al. (2014) considered that this Clade represented the genus Helicomyces based on Helicomyces roseus (CBS 283.51). However, in this study, we found that H. roseus (CBS 283.51) was misidentified and this Clade cannot represent Helicomyces because the morphology of members of Clade 2 does not fit into the generic concept of Helicomyces at all. Therefore, we introduce Pseudohelicomyces gen. nov. to accommodate them.

Clade 3 (1 taxon) represents the new genus Helicotruncatum. We introduce one species herein, Helicotruncatum palmigenum based on phylogeny and morphology.

Clade 4 (7 taxa) represents the genus Helicomyces with four species including H. chiayiensis, H. colligatus, H. hyalosporus and H. torquatus. Helicoma chiayiense (BCRC FU30842) (Kuo and Goh 2018a) is synonymized to Helicomyces chiayiensis.

Clade 5 (1 taxon) represents the new genus Dematiohelicoma.

Clade 6 (11 taxa) represents the genus Neohelicomyces established by Luo et al. (2017). We introduce Neohelicomyces hyalosporus sp. nov. and revisit Helicosporium pallidum (CBS 962.69), H. pallidum (UAMH10535), Tubeufia helicomyces (CBS 271.52) and T. paludosa (CBS 245.49). Helicosporium pallidum is synonymized to Neohelicomyces pallidus. The isolates Tubeufia helicomyces (CBS 271.52) and T. paludosa (CBS 245.49) are identified as Neohelicomyces pallidus based on their identical DNA sequence data. The isolates Tubeufia helicomyces (MUCL 15702) and T. amazonensis (ATCC 42524) cluster with other species of Neohelicomyces. Because of a lack of morphological information (Kodsueb et al. 2006; Tsui et al. 2006; Tsui and Berbee 2006), we do not change their status until new collections and molecular data are available.

Clade 7 (4 taxa) represents the well supported monophyletic genus Muripulchra established by Luo et al. (2017).

Clade 8 (44 taxa) represents the genus Neohelicosporium introduced by Lu et al. (2018). We introduce 18 new isolates and synonymize Helicoma morganii (CBS 281.54), H. violaceum (CBS 222.58), Helicosporium abuense (CBS 101688), H. griseum (CBS 961.69), H. griseum (UAMH 1694), H. lumbricoides (JCM 9265), H. panachaeum (CBS 257.59) (Tsui et al. 2006), H. taiwanense (BCRC FU30841) (Kuo and Goh 2018a), Helicomyces bellus (CBS 113542) (Tsui et al. 2006) and Tubeufia aurantiella (ANM 718) (Promputtha and Miller 2010) under Neohelicosporium. We rename Helicomyces macrofilamentosus (HKUCC 10235) (Kodsueb et al. 2006) and H. torquatus (CBS 189.95) (Tsui et al. 2006) as Neohelicosporium sp. as they have been misidentified and available descriptions do not fit them into the generic concept of Neohelicosporium. Currently, there are only sequence data deposited by previous authors with no morphological description.

Clade 9 (1 taxon) represents the genus Boerlagiomyces introduced by Butzin (1977). The phylogenetic relationships of Boerlagiomyces have been detailed by Doilom et al. (2017).

Clade 10 (1 taxon) represents the genus Manoharachariella which was accepted as a member of Tubeufiaceae by Doilom et al. (2017) based on phylogeny and morphological evidence.

Clade 11 (3 taxa) represents the genus Helicodochium which was established by Monteiro et al. (2014).

Clade 12 (3 taxa) represents the new genus Helicohyalinum. The previously described Chlamydotubeufia aquatica (MFLUCC 16–1131) (Brahamanage et al. 2017) is synonymized under Helicohyalinum aquaticum.

Clade 13 (3 taxa) represents the new genus Dematiohelicomyces. Chlamydotubeufia helicospora (MFLUCC 16–0213) (Hyde et al. 2016a) is synonymized under Dematiohelicomyces helicosporus.

Clade 14 (7 taxa) represents the new genus Neochlamydotubeufia represented by two species (N. fusiformis and N. khunkornensis) and Chlamydotubeufia khunkornensis (MFLUCC 10–0117 and MFLUCC 10–0118) (Boonmee et al. 2011) is synonymized under Neochlamydotubeufia khunkornensis.

Clade 15 (5 taxon) represents the new genus Pseudohelicoon. We introduce Pseudohelicoon to accommodate P. gigantisporum and P. subglobosum.

Clade 16 (5 taxa) represents the genus Helicotubeufia established by Liu et al. (2018).

Clade 17 (5 taxa) represents the genus Aquaphila introduced by Goh et al. (1998). Tsui et al. (2007) accepted Aquaphila as a member of Tubeufiaceae based on phylogenetic analyses.

Clade 18 (6 taxa) represents the genus Chlamydotubeufia established by Boonmee et al. (2011).

Clade 19 (2 taxa) represents the genus Tamhinispora established by Rajeshkumar and Sharma (2013).

Clade 20 (1 taxon) represents the new genus Pleurohelicosporium while Clade 21 (1 taxon) represents the genus Neotubeufia introduced by Chaiwan et al. (2017).

Clade 22 (17 taxa) represents the genus Helicosporium established by Nees (1817) based on the type species H. vegetum. In this study, we introduced five new species in this genus based on phylogenetic analyses and morphological data. We reappraise Helicosporium species and redefine the generic concept. Acanthostigma patagonicum (BBB MVB 573) (Sanchez et al. 2012) and Helicoma vaccinii (CBS 216.90) (Tsui et al. 2006) clustered in this clade. Boonmee et al. (2014) referred to them as Helicosporium patagonicum and H. vaccinii in their phylogeny tree, but did not synonymize them. Brahamanage et al. (2017), Chaiwan et al. (2017) and Lu et al. (2017a) followed Boonmee’s treatment and referred to these two isolates as Helicosporium without detailed morphological verification. However, available morphological descriptions do not tally with species concepts of Helicosporium species, therefore, we retain the original names of these two species until further phylogenetic and morphological data are available.

Clade 23 (2 taxa) represents the genus Acanthostigma established by de Notaris (1863) and phylogenetic relationships have been detailed by Boonmee et al. (2011, 2014). The isolate Helicosporium gracile (CBS 284.54) (Tsui et al. 2006) shares a close relationship to Acanthostigma chiangmaiensis and A. perpusillum, but without bootstrap support. A close affiliation of Helicosporium gracile to Acanthotubeufia and Thaxteriellopsis is also noted in our phylogeny, but there is no support for these relationships. We do not synonymize Helicosporium gracile due to its unclear morphological descriptions in previous studies (Morgan 1892; Linder 1929; Goos 1989; Zhao et al. 2007). Therefore, we rename the isolate CBS 284.54 as Tubeufiaceae sp. to suggest that further studies are undertaken to ascertain its identification.

Clade 24 (7 taxa) represents the genus Thaxteriellopsis established by Sivanesan et al. (1976) with Thaxteriellopsis lignicola as the type species. Two new isolates of T. lignicola are introduced in this paper with details on morphological characteristics and DNA sequence data.

Clade 25 (2 taxa) represents the new genus Acanthotubeufia. We synonymize Acanthostigma filiforme (ANM 101 and ANM 514) (Promputtha and Miller 2010) under Acanthotubeufia filiforme.

Clade 26 (1 taxon) represents the genus Helicangiospora which was established by Boonmee et al. (2014) with H. lignicola as the type species.

Clade 27 (5 taxa) represents the genus Acanthostigmina established by von Höhnel (1909) with Acanthostigmina minuta as the type species. Our phylogeny reveals some interesting findings pertaining to the taxonomy of these isolates. It is noted that these five taxa are segregated in three subclades that could represent different species. However, we refrain from changing their taxonomic status due to lack of morphological data and suggest further studies be undertaken. Besides, the isolate Helicosporium sp. (UBC F14999) (Tsui et al. 2006) is basal to Acanthostigmina, but Tsui et al. (2006) did not describe its morphology, thus, we renamed it as Tubeufiaceae sp. and suggest further studies be undertaken to ascertain its identification.

Clade 28 (31 taxa) represents the genus Helicoma established by Corda (1937) based on the type species Helicoma muelleri. In this study, we report 14 newly obtained isolates belonging to ten species. Helicosporium hongkongense and H. nematosporum are synonymized under Helicoma. The isolate MFLUCC 12–0563 (Doilom et al. 2017) is revisited and identified as Helicoma tectonae, and Thaxteriella helicoma (UBC F13877) (Tsui et al. 2006) as Helicoma muelleri (UBC F13877). Helicoma conicodentatum (UAMH 10534) is synonymized under Helicoma ambiens. We rename the isolate Tubeufia paludosa (HKUCC 9118) (Kodsueb et al. 2006) as Helicoma sp. (HKUCC 9118) and suggest that further studies be undertaken to ascertain its identification.

Clade 29 (3 taxa) represents the genus Kamalomyces established by Verma et al. (2008) with K. indicus as the type species. Phylogenetic relationships of Kamalomyces, with K. bambusicola and K. thailandicus were first reported by Phookamsak et al. (2018).

Clade 30 (1 taxon) represents the new genus Dematiotubeufia. Helicoma chiangraiensis (MFLUCC 10–0115) (Boonmee et al. 2014) is synonymized to Dematiotubeufia chiangraiensis based on phylogenetic analyses and morphology.

Clade 31 (1 taxon) represents the new genus Neohelicoma. We synonymize Helicoma fagacearum (MFLUCC 11–0379) (Boonmee et al. 2014) under N. fagacearum.

Clade 32 (1 taxon) represents the new genus Helicoarctatus.

Clade 33 (7 taxa) represents the genus Acanthohelicospora established by Boonmee et al. (2014). We synonymize Helicosporium guianensis (UAMH 1699) (Tsui et al. 2006) under Acanthohelicospora guianensis and the latter is closely related to A. pinicola, however there was no support for this subclade. There was no support either for any relationships of Acanthohelicospora to Dictyospora.

Clade 34 (5 taxa) represents the genus Dictyospora (represented herein by D. thailandica) established by Brahamanage et al. (2017). In this study, we report an isolate of D. thailandica bearing slightly different morphs.

Clade 35 (30 taxa) represents the genus Berkleasmium established by Zobel (Corda 1854) with the type species B. concinnum. Tanney and Miller (2017) found that B. concinnum is the asexual morph of Neoacanthostigma septoconstrictum. In this study, we synonymize Neocanthostigma aquaticum, N. brunneisporum, N. guangxiense, N. latisporum, N. thailandicum and introduce two new species, Berkleasmium fusiforme and B. longisporum.

Clade 36 (1 taxon) represents the genus Neoacanthostigma established by Boonmee et al. (2014) with the type species N. fusiforme.

Clade 37 (1 taxon) represents the new genus Dematiohelicosporum. We introduce this genus with Dematiohelicosporum guttulatum as the type species.

Taxonomy

Acanthohelicospora Boonmee & K.D. Hyde, Fungal Diversity 68(1): 251 (2014)

Index Fungorum: IF 550572; Facesoffungi number: FoF 00206

Saprobic on decaying wood. Sexual morph Ascomata superficial, seated on a subiculum, solitary, scattered, globose to subglobose, surrounded by black setae, dark brown to black, with a central ostiole. Setae tapering to an acute apex, thick-walled, dark brown to black, straight, covering the whole ascomata. Peridium composed of several layers cells of textura angularis, with inner cells pale brown and outer cells dark brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores fasciculate, fusiform, tapering towards the rounded ends, slightly curved, guttulate, multi-septate, not constricted at septa, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, hyaline to yellow green. Mycelium composed of partly immersed, partly superficial, brown to dark brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, erect, setiferous, cylindrical, septate, brown to dark brown, smooth-walled. Conidiogenous cells holoblastic, monoblastic, discrete, determinate, denticulate, arising laterally from the lower parts of conidiophores as tiny tooth-like or bladder-like protrusions, hyaline to pale brown. Conidia solitary, pleurogenous, helicoid, rounded at tip, multi-septate, guttulate, hyaline, smooth-walled (Boonmee et al. 2014; Lu et al. 2017a).

Type species: Acanthohelicospora pinicola Boonmee & K.D. Hyde, Fungal Diversity 68(1): 251 (2014)

Notes: The genus Acanthohelicospora was introduced by Boonmee et al. (2014) based on morphology and phylogenetic evidence. Its sexual morph is characterized by superficial ascomata covered by setae which taper to an acute apex, 8-spored, bitunicate asci and slightly curved, fusiform ascospores, which taper towards rounded ends (Boonmee et al. 2014). Its asexual morph is characterized by helicosporous hyphomycetes, which are similar to Helicosporium in conidiophores, conidiogenous cells and conidial morphology (Lu et al. 2017a). Four species are accommodated in this genus including our new combination Acanthohelicospora guianensis.


Acanthohelicospora guianensis (Linder) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium guianense Linder [as ‘guianensis’], Ann. Mo. bot. Gdn 16: 280 (1929)

Index Fungorum: IF 554811; Facesoffungi number: FoF 04753

Type: British Guiana, Georgetown, 4 October 1923, Linder, TYPE (F).

Possible distribution: British Guiana, Brazil, China, Cuba, India, Mexico, New Guinea, Panama.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Linder (1929, as Helicosporium guianensis), Matsushima (1971, as Helicosporium guianensis), Goos (1989, as Helicosporium guianense) and Zhao et al. (2007, as Helicosporium guianense).

Notes: This taxon was introduced as Helicosporium guianensis by Linder (1929). Matsushima (1971) reported a new record of H. guianensis. Goos (1989) reexamined and described this taxon. Tsui et al. (2006) reported a new record and provided its ITS and LSU sequence data (UAMH 1699). Zhao et al. (2007) introduced a new record from China. Boonmee et al. (2014) renamed this taxon as Acanthohelicospora guianense but did not synonymize it. Lu et al. (2017a) mentioned that Helicosporium guianense should be transferred to Acanthohelicospora but did not synonymize it either. Our phylogenetic tree showed that the isolate UAMH 1699 shares a sister relationship to the type species Acanthohelicospora pinicola. Besides, based on previous studies, its morphology is similar to Acanthohelicospora aurea in having setiferous conidiophores, bladder-like protrusions conidiogenous cells and pleurogenous helicoid conidia (Linder 1929, as Helicosporium aureum; Goos 1989, as H. aureum; Zhao et al. 2007, as H. aureum; Lu et al. 2017a). Therefore, we synonymize it under Acanthohelicospora guianensis.

Other accepted Acanthohelicospora species

Acanthohelicospora aurea (Corda) Rossman & W.C. Allen, IMA Fungus 7(1): 2 (2016)

≡ Helicomyces aureus Corda, Icon. fung. (Prague) 1: 9 (1837)

≡ Helicosporium aureum (Corda) Linder, Ann. Mo. bot. Gdn 16: 279 (1929)

= Helicosporium citreoviride Tubaki, Trans. Mycol. Soc. Japan 5: 2 (1964)

Index Fungorum: IF 815416

Possible distribution: Brazil, China (Guangxi▲, Tibet, Yunnan), Japan, Panama, USA (Alabama, Arizona, Connecticut, Florida, Iowa, Louisiana, Maryland, Massachusetts, Missouri).

Habitat: Terrestrial.

Notes: This taxon was introduced as Helicomyces aureus by Corda (1937). Linder (1929) synonymized it under Helicosporium aureum. Goos (1989) synonymized Helicosporium citreoviride under H. aureum. Zhao et al. (2007) reported new records of H. aureum. Rossman et al. (2016) synonymized this taxon under Acanthohelicospora aurea. Lu et al. (2017a) reported new records of A. aurea and linked its sexual-asexual morphs based on phylogenetic analyses.


Acanthohelicospora pinicola Boonmee & K.D. Hyde, Fungal Diversity 68(1): 251 (2014)

Index Fungorum: IF 550573

Known distribution: Thailand.

Habitat: Terrestrial.

Notes: This taxon was introduced by Boonmee et al. (2014) as the type species of Acanthohelicospora based on phylogenetic and morphological analyses.


Acanthohelicospora scopula (Peck) Rossman & W.C. Allen, IMA Fungus 7(1): 2 (2016)

≡ Acanthostigma scopulum Peck, Bull. N.Y. St. Mus. nat. Hist. 1(2): 22 (1887)

= Helicosporium pilosum Ellis & Everh., Bull. Torrey bot. Club 24: 476 (1897)

= Sphaeria scopula Cooke & Peck 1880 (non Sowerby 1803)

= Acanthostigmina scopula (Cooke & Peck) J.L. Crane et al., Canad. J. Bot. 76: 606 (1998)

= Lasiosphaeria scopula (Cooke & Peck) Sacc., Syll. Fung. 9: 852 (1891)

= Tubeufia scopula (Cooke & Peck) M.E. Barr, Mycotaxon 12: 164 (1980)

Index Fungorum: IF 815417

Possible distribution: Austria, Canada, USA (Alabama, Florida, New Jersey, New York).

Habitat: Terrestrial.

Notes: This taxon shares similar morphology to Acanthohelicospora pinicola (Réblová and Barr 2000; Kodsueb et al. 2004; Promputtha and Miller 2010; Boonmee et al. 2014). Boonmee et al. (2014) renamed this taxon as Acanthohelicospora scopulum in their phylogeny tree but did not synonymize it. Rossman et al. (2016) synonymized it to Acanthohelicospora scopula.


Acanthotubeufia Y.Z. Lu & K.D. Hyde, gen. nov.

Index Fungorum: IF 554812; Facesoffungi number: FoF 04696

Etymology: “Acantho-” referring to this genus due to similarities to Acanthostigma, “-tubeufia” referring to the type genus (Tubeufia) of Tubeufiaceae.

Saprobic on decaying wood. Sexual morph Ascomata superficial, scattered or gregarious, globose to subglobose, shiny, black when dry, densely setose. Setae one-celled or rarely one-septate, thick-walled, brown to dark brown, straight to slightly curved, with acute tip. Peridium two-layered in longitudinal section, inner layer composed of 3–5 rows of light brown, thin-walled, flattened to angular cells, outer layer composed of 1–2 rows of dark brown, angular to elongated cells which sometimes produce setae. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical to cylindrical-clavate, broadly rounded and thickened at the apex, short- pedicellate, hyaline, smooth-walled. Ascospores fasciculate, filiform, straight or curved or sometimes sigmoid, tapering and narrowly rounded at both ends, symmetrical at ends, 12–16-septate, not constricted at septa, hyaline, smooth-walled (Promputtha and Miller 2010). Asexual morph Undetermined.

Type species: Acanthotubeufia filiforme (Promp. & A.N. Mill.) Y.Z. Lu & K.D. Hyde

Notes: The new genus Acanthotubeufia is introduced here based on phylogeny and morphological evidence. Our multi-gene phylogenetic analyses showed that two isolates of A. filiforme formed a single clade (Clade 25) and distinct to other genera (Figs. 2, 15). Its morphology is similar to Neoacanthostigma and Acanthostigma in having one-celled or rarely one-septate setae covering the globose to subglobose ascomata, but differs by its longer and narrower and symmetrical filiform ascospores.


Acanthotubeufia filiforme (Promp. & A.N. Mill.) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Acanthostigma filiforme Promp. & A.N. Mill., Mycologia 102(3): 575 (2010)

≡ Neoacanthostigma filiforme (Promp. & A.N. Mill.) Boonmee & K.D. Hyde, Fungal Diversity 68(1): 279 (2014)

Index Fungorum: IF: 554813; Facesoffungi number: FoF 04706

Type: USA, Tennessee, Blount County, Great Smoky Mountains National Park, vicinity of Townsend, Cades Cove, Willie Myers, decorticated branch on ground, 14 Jul 2004, A.N. Miller, S.M. Huhndorf, G.K. Mugambi, ANM101 (ILLS 59352, holotype).

Known distribution: USA (North Carolina, Tennessee).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Promputtha and Miller (2010, as Acanthostigma filiforme).

Notes: This taxon was introduced as Acanthostigma filiforme by Promputtha and Miller (2010). Boonmee et al. (2014) synonymized it under Neoacanthostigma filiforme based on phylogenetic evidence. However, Tanney and Miller (2017) pointed out that the transfer of Acanthostigma filiforme to Neoacanthostigma was unwarranted based on ITS-LSU phylogenetic analyses. Our phylogenetic analyses also showed that two taxa of A. filiforme (ANM101 and ANM514) formed a distinct clade from Neoacanthostigma and Acanthostigma. Furthermore, its morphology differs from Neoacanthostigma and Acanthostigma species in ascospores. The ascospore of Acanthostigma filiforme are fasciculate, filiform, and symmetrical at both ends, and its length is similar to the ascus, but the ascospores of Neoacanthostigma and Acanthostigma species are fusiform, 2–3-seriate, and obviously shorter than their asci. Therefore, we synonymize it under Acanthotubeufia filiforme.


Artocarpomyces Subram., Kavaka 22/23: 52 (1996) [1994]

Index Fungorum: IF 28736

Saprobic on decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, dictyosporous. Stroma brown, pseudparenchymatous. Conidiophores arising from stroma, micronematous to macronematous, simple, brown to dark brown, apparently aseptate, robust, or with a few septa. Conidiogenous cells integrated, apical, brown, verrucose. Conidia solitary, monoblastic, dry, brown to black, muriform, variable in shape, ovoid to irregular and resembling the fruit of Artocarpus (jackfruit), globose or subglobose, tuberculate, non-deciduous, detached with a bit of conidiogenous cell or conidiophore remaining as a pedicel. A conidium may often produce a short conidiogenous cell on which a further conidium may be produced (Subramanian 1994).

Type species: Artocarpomyces paradoxus Subram. [as ‘paradoxa’], Kavaka 22/23: 52 (1996) [1994]

Notes: Artocarpomyces was introduced by Subramanian (1994) with the type species Artocarpomyces paradoxus. It is characterized by macronematous conidiophores, arising from a brown pseudoparenchymatous stroma, and conidia are muriform, variable in shape, irregular and resembling the fruit of Artocarpus. This genus has previously been referred to genera incertae sedis within Ascomycota (Wijayawardene et al. 2017a, b, 2018). In this study, we accept Artocarpomyces as a genus of Tubeufiaceae based on its morphological resemblance to Tubeufia chlamydospora and T. dictyospora. For example, Artocarpomyces paradoxus is also characterized by muriform, ovoid to irregular conidia which are variable in shape, that are also present in Tubeufia.


Berkleasmium Zobel, Icon. fung. (Prague) 6: 4 (1854)

Index Fungorum: IF 7362

Saprobic on decaying wood. Sexual morph Ascomata superficial, seated on a subiculum, solitary, scattered, subglobose to globose, dark brown to black, with a central ostiole. Setae multi-celled (Fig. 3j–l), thick-walled, brown to black, straight or slightly curved, covering the whole ascomata. Peridium composed of several layers cells of textura angularis, with inner cells pale brown and outer cells dark brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores biseriate, fusiform, tapering towards the rounded ends, slightly curved, guttulate, multi-septate, not constricted at septa, hyaline, smooth-walled (Fig. 3). Asexual morph (1) Hyphomycetous, with dictyoconidia; Sporodochia black, distinct, about 0.2 mm in diameter, compact, where crowded tending to become confluent; conidia broad-cylindrical, multicellular, with large and fairly regular cells, fuscous, borne on short conidiophores which become obscure with maturity (Moore 1958). (2) Hyphomycetous, helicosporous; colonies on the substratum superficial, effuse, gregarious, brown; mycelium composed of partly immersed, partly superficial, brown, septate, branched hyphae, with masses of crowded, glistening conidia; conidiophores macronematous, mononematous, erect, arising as lateral branches from creeping hyphae, short, cylindrical, 0–3-septate, brown, smooth-walled; conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, truncate at apex, brown, smooth-walled; conidia solitary, acrogenous, helicoid, tapering to apex and base, coiled 1½–3½ times, becoming loosely coiled or uncoiled in water, with elongated basal cell, rounded at tip, multi-septate, slightly constricted at septa, 90–180 μm diam. and conidial filament 8–15 μm wide, more than 400 μm long, up to 1540 μm long, brown, smooth-walled.

Fig. 3
figure 3

The sexual morph of Berkleasmium. a–e Superficial ascomata on substrate. Note ascomata surrounded by black setae. f–i Asci. j–l Setae. m–q Ascospores. Scale bars: a–e = 200 µm, f–i = 50 µm, j–q = 20 µm

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Type species: Berkleasmium concinnum (Berk.) S. Hughes, Can. J. Bot. 36: 740 (1958)

Notes: The genus Berkleasmium was introduced by Zobel (Corda 1854). Moore (1958) re-established Berkleasmium to accommodate sporodochial species previously placed in Sporidesmium. Berkleasmium currently comprises 37 species characterized by sporodochial conidiomata bearing macronematous conidiophores, monoblastic conidiogenous cells and brown or black, dry, rhexolytically-seceding dictyoconidia (Moore 1958; Ellis 1971; Bussaban et al. 2001; Zhao and Zhang 2004; Pinnoi et al. 2007; Seifert et al. 2011; Qu et al. 2014; Tanney and Miller 2017). Tanney and Miller (2017) reported that the type species of Berkleasmium, B. concinnum, was the asexual morph of Neoacanthostigma septoconstrictum. Their phylogenetic analyses confirmed this asexual-sexual morph connection, and re-examination of reference specimens also revealed the co-occurrence of N. septoconstrictum ascomata and B. concinnum sporodochia (Tanney and Miller 2017). In this study, our multi-gene phylogenetic analysis showed that B. concinnum grouped with Neocanthostigma aquaticum, N. guangxiense, N. latisporum, N. thailandicum and two new taxa, Berkleasmium fusiforme and B. longisporum with high support (Fig. 2, Clade 35), apart from the type species of Neoacanthostigma (Neoacanthostigma fusiforme MFLUCC 11–0510). Morphologically, the sexual morph of B. concinnum is similar to N. aquaticum, N. thailandicum (Lu et al. 2017c as N. brunneisporum) and B. fusiforme (this study) in having superficial ascomata seated on a subiculum, subglobose to globose, dark brown to black, multi-celled setae covering the whole ascoma, 8-spored, bitunicate, cylindrical, pedicellate asci, and fusiform, slightly curved ascospores with tapering rounded ends. Accordingly, we considered that these six species, viz. B. fusiforme, B. longisporum, N. aquaticum, N. guangxiense, N. latisporum and N. thailandicum should be accommodated in Berkleasmium even though their asexual morphs are unclear, but supported by strong phylogenetic evidence, as well as similar sexual morph characteristics (Fig. 3). We did not accept other previously described as Berkleasmium species under Tubeufiaceae because of a lack of phylogenetic and morphological evidence. In this study, we introduced two new Berkleasmium species and four new combinations. We accept seven Berkleasmium species within the family Tubeufiaceae.


Berkleasmium fusiforme Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554814; Facesoffungi number: FoF 04697; Fig. 4

Fig. 4
figure 4

Berkleasmium fusiforme (MFLU 17–1120, holotype). a Superficial ascomata on substrate. Note ascomata surrounded by black setae. b Ascoma. c Peridium. d Seta. e–h Asci. i–k Ascospores. l Germinating ascospore. m, n Colonies on PDA from above and below. Scale bars: a = 200 µm, b, c = 100 µm, d–i = 20 µm, j–l = 10 µm

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Holotype: MFLU 17–1120

Etymology: “fusiforme” referring to the fusiform ascospores of this fungus.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Ascomata 220–290 μm high × 240–300 μm diam., superficial, solitary, scattered, subglobose to globose, seated on a subiculum, dark brown to black, with a central ostiole. Setae 40–55 μm long, 4–6 μm wide, 1–3-celled, thick-walled, brown to black, straight, covered the whole ascoma. Peridium 45–60 μm thick, composed of several layered cells of textura angularis, with inner cells pale brown and outer cells dark brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 100–140 × 14–19 μm (\( \bar{x} \) = 119 × 16.5 μm, n = 20), 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores 45–55 × 5–6 μm (\( \bar{x} \) = 50 × 5.5 μm, n = 50), biseriate, fusiform, tapering towards rounded ends, slightly curved, guttulate, 6–7-septate, not constricted at septa, hyaline, smooth-walled. Asexual morph Undetermined.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 24 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 17 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on decaying wood in a dry stream, 27 April 2017, Yong-Zhong Lu, TD03 (MFLU 17–1120, holotype; HKAS 100790, isotype), ex-type living cultures, MFLUCC 17–1978, TBRC; Ibid., TD04 (MFLU 17–1121 = HKAS 100791, paratype), living culture, MFLUCC 17–1979; Ibid., TD13 (MFLU 17–1127 = HKAS 100799, paratype), living culture, MFLUCC 17–1987; Ibid., TD14 (MFLU 17–1128 = HKAS 100780, paratype), living culture, MFLUCC 17–1988.

Notes: Morphologically, Berkleasmium fusiforme is similar to B. aquaticum (Lu et al. 2017c, as Neoacanthostigma aquaticum) and B. concinnum (Promputtha and Miller 2010, as Acanthostigma septoconstrictum) in having superficial, subglobose to globose ascomata, 1–3-celled setae covered the whole ascoma, 8-spored, bitunicate, cylindrical, pedicellate asci, and fusiform, slightly curved ascospores tapering towards the rounded ends. Berkleasmium fusiforme can be distinguished from B. aquaticum by its wider ascomata (240–300 vs. 180–225 μm diam.) and thicker peridium (45–60 vs. 25–34 μm thick), and from B. concinnum by its wider ascomata (240–300 vs. 150–200 μm diam.) and shorter setae (40–55 vs. 42–120 μm long) and different number of septa (6–7-septate vs. 7–10-septate). Phylogenetically, four isolates of B. fusiforme constitute a strongly supported subclade, sister to B. guangxiense with good bootstrap support (Fig. 2). The phylogeny supports that B. fusiforme is a distinct species.


Berkleasmium longisporum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum number: IF 554815; Facesoffungi number: FoF 04698; Fig. 5

Fig. 5
figure 5

Berkleasmium longisporum (MFLU 17–1139, holotype). a Colony on decaying wood. b–f Conidiophores and conidiogenous cells. g Conidiogenous cell with attached conidium. h–j Conidiogenous cells with a part of attached conidia. k–n Conidia. o, p Colonies on PDA from above and below. q Umbonate colony surface on PDA from above. Scale bars: a = 200 µm, b–f, h–j = 20 µm, g, k–n = 100 µm

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Holotype: MFLU 17–1139

Etymology: “longisporum” referring to the long helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium composed of partly immersed, partly superficial, brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, erect, arising as lateral branches from creeping hyphae, cylindrical, 0–3-septate, 15–40 × 5–7 μm, brown, smooth-walled. Conidiogenous cells monoblastic, holoblastic, integrated, sympodial, terminal, cylindrical, truncate at apex, 10–26 μm long, 5–7 μm wide, brown, smooth-walled. Conidia solitary, acrogenous, helicoid, basal cell elongated, rounded at tip, 110–180 μm diam. and conidial filament 11–15 μm wide in the broadest part (\( \bar{x} \) = 145 × 12.5 μm, n = 20), tapering to 4.5–5.5 μm wide near apex and base, 1190–1540 μm long, 100–122-septate, slightly constricted at septa, coiled 2–3 times, becoming loosely coiled or uncoiled in water, brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with umbonate surface, obviously wrinkled, edge entire, reaching 13 mm in 2 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW08 (MFLU 17–1139, holotype; HKAS 100810, isotype), ex-type living cultures, MFLUCC 17–1999, TBRC; Ibid., TW02 (MFLU 17–1130, paratype), living culture, MFLUCC 17–1990; Ibid., TW11 (MFLU 17–1142 = HKAS 100813, paratype), living culture, MFLUCC 17–2002.

Notes: Berkleasmium longisporum is morphologically similar to Berkleasmium latisporum (Lu et al. 2017c, as Neoacanthostigma latisporum) and Berkleasmium thailandicum (Lu et al. 2017c, as Neoacanthostigma brunneisporum) in having brown colony with masses of crowded, glistening conidia on natural decaying woody substrate, and 0–3-septate, erect, cylindrical conidiophores, terminal, cylindrical conidiogenous cells with truncate ends on conidial secession, and large-sized helicoid conidia. However, B. longisporum can be easily distinguished by its obviously longer conidia and larger conidial septa (1190–1540 μm long, up to 122-septate) from B. latisporum (540–760 μm long, up to 60-septate) and B. brunneisporum (630–950 μm long, up to 60-septate). Phylogenetically, our three isolates of B. longisporum shares a sister relationship to B. latisporum with good bootstrap support (100% MLBS, 1.00 PP) (Fig. 2), and phylogeny also supports it as a distinct species.

New combinations of Berkleasmium


Berkleasmium aquaticum (Y.Z. Lu, Boonmee & K.D. Hyde) Y.Z. Lu, comb. nov.

≡ Neoacanthostigma aquaticum Y.Z. Lu, Boonmee & K.D. Hyde, Cryptog. Mycol. 38(2): 176 (2017)

Index Fungorum: IF 554816; Facesoffungi number: FoF 04786

Type: CHINA, Guangxi Province, Fangchenggang City, on decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, HKAS 97431 (holotype).

Known distribution: China (Guangxi).

Habitat: Aquatic.

Description: For a complete description of this taxon see Lu et al. (2017c, as Neoacanthostigma aquaticum).

Notes: This taxon was introduced as Neoacanthostigma aquaticum by Lu et al. (2017c). Its sexual morph resembles Berkleasmium concinnum (Acanthostigma septoconstrictum as in Promputtha and Miller 2010) in ascomata, asci and ascospores. Our phylogenetic analyses showed that seven isolates of N. aquaticum cluster within the genus Berkleasmium. Therefore, we synonymize N. aquaticum to Berkleasmium aquaticum.


Berkleasmium guangxiense (Y.Z. Lu, Boonmee & K.D. Hyde) Y.Z. Lu, comb. nov.

≡ Neoacanthostigma guangxiense Y.Z. Lu, Boonmee & K.D. Hyde, Cryptog. Mycol. 38(2): 182 (2017)

Index Fungorum: IF 554817; Facesoffungi number: FoF 04787

Type: CHINA, Guangxi Province, Fangchenggang City, on decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, HKAS 97425 (holotype).

Known distribution: China (Guangxi).

Habitat: Aquatic.

Description: For a complete description of this taxon see Lu et al. (2017c, as Neoacanthostigma guangxiense).

Notes: This taxon was introduced as Neoacanthostigma guangxiense by Lu et al. (2017c). We synonymize it under Berkleasmium guangxiense based on phylogenetic evidence. Berkleasmium guangxiense shares a sister relationship to B. fusiforme with high bootstrap support (100% MLBS, 1.00 PP) (Fig. 2).


Berkleasmium latisporum (Y.Z. Lu, Boonmee & K.D. Hyde) Y.Z. Lu, comb. nov.

≡ Neoacanthostigma latisporum Y.Z. Lu, Boonmee & K.D. Hyde, Cryptog. Mycol. 38(2): 184 (2017)

Index Fungorum: IF 554818; Facesoffungi number: FoF 04788

Type: THAILAND, Uttaradit, Laplae, Mae Phun, Ban Ton Klua, on decaying wood in flowing freshwater stream, 24 October 2015, Saranyaphat Boonmee, MFLU 17–0336 (holotype).

Known distribution: Thailand.

Habitat: Aquatic.

Description: For a complete description of this taxon see Lu et al. (2017c, as Neoacanthostigma latisporum).

Notes: This taxon was introduced as Neoacanthostigma latisporum by Lu et al. (2017c). We synonymize it under Berkleasmium latisporum based on phylogenetic evidence. Berkleasmium latisporum shares a sister relationship to B. longisporum with high bootstrap support (100% MLBS, 1.00 PP) (Fig. 2).


Berkleasmium thailandicum (Tanney & A.N. Mill) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Neoacanthostigma thailandicum Tanney & A.N. Mill., IMA Fungus 8(1): 103 (2017)

≡ Neoacanthostigma brunneisporum Y.Z. Lu, Boonmee & K.D. Hyde, Cryptog. Mycol. 38(2): 179 (2017)

Index Fungorum: IF 554819; Facesoffungi number: FoF 04789

Holotype: MFLU 16–1134

Known distribution: Thailand.

Habitat: Aquatic, Terrestrial.

Description: For a complete description of this taxon see Lu et al. (2017c, as Neoacanthostigma brunneisporum).

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on decaying wood in a dry stream, 27 April 2017, Yong-Zhong Lu, TD10 (MFLU 17–1126 = HKAS 100796), living culture, MFLUCC 17–1984; Ibid. on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW09 (MFLU 17–1140 = HKAS 100811), living culture, MFLUCC 17–2000.

Notes: This taxon was introduced as Neoacanthostigma septoconstrictum (MFLU 16–1134) by Hyde et al. (2016a). Tanney and Miller (2017) described it as Neoacanthostigma thailandicum based on morphological data and DNA sequence data. Simultaneously, Lu et al. (2017c) also pointed out that this species was distinct from N. septoconstrictum, and N. brunneisporum was therefore introduced for this taxon. In this study, our multi-gene phylogenetic tree indicates that this taxon should be accommodated in Berkleasmium. Hence, N. thailandicum and N. brunneisporum are synonymized under B. thailandicum because of the priority of “B. thailandicum” over “B. brunneisporum” (Tanney and Miller 2017; Lu et al. 2017c). Furthermore, we noted that our two new isolates of B. thailandicum (MFLUCC 17–1984 and MFLUCC 17–2000) are phylogenetically slightly apart from the other four known isolates. Following the recommendation of Jeewon and Hyde (2016) for delimitation of new species, we looked into pair wise dissimilarities of DNA sequences and noted that there are three and six noticeable nucleotide differences between our new isolates and other four known isolates in ITS and TEF1α sequence data, respectively. However, we could not find any morphological features to distinguish them, thus, we identify our two new isolates as B. thailandicum.

Other accepted Berkleasmium species within Tubeufiaceae


Berkleasmium concinnum (Berk.) S. Hughes, Canad. J. Bot. 36: 740 (1958)

≡ Sporidesmium concinnum Berk., London J. Bot. 4: 309 (1845)

= Berkleasmium cordeanum Zobel, in Corda, Icon. Fung. 6: 4 (1854); nom. illegit. (Art. 52.1)

= Neoacanthostigma septoconstrictum (Promp. & A.N. Mill.) Boonmee & K.D. Hyde, Fungal Diversity 68: 279 (2014)

= Acanthostigma septoconstrictum Promp. & A.N. Mill., Mycologia 102: 579 (2010)

Index Fungorum: IF 293662

Possible distribution: Canada (Quebec), Japan, Russia (Primorsky Krai), USA (Louisiana, Massachusetts, Missouri, New York, North Carolina, Ohio, South Carolina, Tennessee, West Virginia, Wisconsin).

Habitat: Terrestrial.

Notes: Berkleasmium concinnum is the type species of Berkleasmium. Tanney and Miller (2017) linked its asexual-sexual morphs based on phylogenetic analyses.


Chaetosphaerulina I. Hino, Bull. Miyazaki Coll. Agric. Forest. 10: 62 (1938)

Index Fungorum: IF 971

Type species: Chaetosphaerulina yasudae I. Hino, Bull. Miyazaki Coll. Agric. Forest. 10: 62 (1938)

Possible distribution for type species: India, Japan, Sierra Leone, Tanzania.

Description: For a complete description of this genus see Hino (1938) and Boonmee et al. (2011).

Notes: Chaetosphaerulina was introduced by Hino (1938) based on the type species Chaetosphaerulina yasudae. Pirozynski (1972) transferred C. yasudae and C. vermicularispora to Herpotrichia. Sivanesan (1984) transferred these two species to Tubeufia. Rossman (1987) accepted Pirozynski’s evaluation. Crane et al. (1998) pointed out that Chaetosphaerulina must be reinstated to include species that form elongate, multiseptate ascospores, often with one to a few cells containing vertical septa. Meanwhile, Thaxteriellopsis bambusicola and T. lignicola have been transferred to Chaetosphaerulina (Crane et al. 1998). Boonmee et al. (2011) accepted Crane’s evaluation for Thaxteriellopsis bambusicola but reinstated T. lignicola as the type species of Thaxteriellopsis based on morphology and phylogeny. Boonmee et al. (2014) excluded Chaetosphaerulina from Tubeufiaceae due to a lack of sufficient evidence. Wijayawardene et al. (2018) listed Chaetosphaerulina within Tubeufiaceae. The morphology of Chaetosphaerulina described in previous studies (Hino 1938; Alaka and Rao 1997; Crane et al. 1998; Boonmee et al. 2011) were similar to Thaxteriellopsis and Tubeufia, therefore, we accept Chaetosphaerulina as a member of Tubeufiaceae. Five species were accepted in this genus, viz. Chaetosphaerulina bambusae, C. bambusicola, C. eucalypti, C. vermicularispora and C. yasudae (Hino 1938; Alaka and Rao 1997; Crane et al. 1998; Boonmee et al. 2011).


Chlamydotubeufia Boonmee & K.D. Hyde, Fungal Diversity 51(1): 78 (2011)

Index Fungorum: IF 563500

Known distribution for type species: Thailand.

Saprobic on decaying wood. Sexual morph Ascomata superficial, solitary or scattered, globose to subglobose, dark brown to black, setose, coriaceous, with a central ostiole. Ostiole single, central. Setae covering the whole ascoma, dark brown to black, taper to an acute apex, unbranched, thick-walled. Peridium composed of several layers of cells of textura angularis. Hamathecium of branched pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, cylindrical to clavate, saccate, apically rounded, short pedicellate. Ascospores 2–3-seriate fusiform, straight to slightly curved, tapering toward the ends, guttulate, multi-septate, not constricted at the septa, hyaline to pale brown. Asexual morph Hyphomycetous, chlamydosporous or helicosporous. Conidiophores lacking. Chlamydospores holoblastic, broadly oval to ellipsoid, dictyoseptate, pale brown when immature, darkened to black when matured, with terminal cells round and subhyaline. Helicosporous asexual morph found from chlamydosporous cultures (Shearer 1987): Conidiophores macronematous, mononematous, erect, cylindrical, unbranched, 0–3-septate, arising as lateral branches from creeping hyphae, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, with denticles, hyaline to pale brown, smooth-walled. Conidia solitary, acrogenous, helicoid, circinate, non-hygroscopic, with U-shaped basal cell, rounded at end, 2–6-septate, slightly constricted at septa, coiled 1¼–1¾ times, hyaline, smooth-walled.

Type species: Chlamydotubeufia huaikangplaensis Boonmee & K.D. Hyde, Fungal Diversity 51(1): 78 (2011)

Notes: The genus Chlamydotubeufia was introduced by Boonmee et al. (2011) to accommodate four species, viz. Chlamydotubeufia chlamydospora, C. depressispora, C. huaikangplaensis and C. khunkornensis. Hyde et al. (2016a) introduced C. helicospora and Brahamanage et al. (2017) introduced C. aquatica within this genus based on phylogenetic evidence. However, our multi-gene phylogenetic analysis (Fig. 2) show that C. aquatica, C. helicospora and C. khunkornensis clustered in distinct clade which is far away from Chlamydotubeufia sensu stricto clade (Clade 18) which includes the type C. huaikangplaensis, and Liu et al. (2018) obtained the similar results. Therefore, we exclude Chlamydotubeufia aquatica, C. helicospora and C. khunkornensis from Chlamydotubeufia. In this paper, we accept five species in the genus Chlamydotubeufia, and exclude three species.


Chlamydotubeufia cylindrica Y.Z. Lu, Boonmee & K.D. Hyde, sp. nov.

Index Fungorum number: IF 554820; Facesoffungi number: FoF 04699; Figs. 6 and 7

Fig. 6
figure 6

The sexual morph of Chlamydotubeufia cylindrica (MFLU 17–1177, holotype). a, b Superficial ascomata on substrate. Note ascomata surrounded by black setae. c, d Ascoma. e Peridium. f Seta. g–i Asci. j–o Ascospores. Scale bars: a, b = 200 µm, c, d = 100 µm, e–o = 20 µm

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Fig. 7
figure 7

The asexual morph of Chlamydotubeufia cylindrica (from ex-type living cultures). a Germinating ascospore. b, c Colony on MEA from above and below. d–f Mycelium and conidiophores. g–m Chlamydospores. Scale bars: a, g–m = 20 µm, d–f = 50 µm

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Holotype: MFLU 17–1177

Etymology: “cylindrica” referring to the cylindrical asci of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Ascomata 175–225 high × 175–250 μm diameter (\( \bar{x} \) = 205 × 200 μm, n = 10), superficial, solitary or scattered, globose to subglobose, black, setose, coriaceous, with a central ostiole. Ostiole single, central. Setae 40–65 × 5–6 μm, covering the whole ascoma, dark brown to black, taper to an acute apex, unbranched, thick-walled. Peridium 25–30 μm thick, composed of several layers of cells of textura angularis. Hamathecium of 1–2 μm wide, branched pseudoparaphyses. Asci 90–110 × 15–18 μm (\( \bar{x} \) = 100 × 16 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical to clavate, saccate, apically rounded, short-pedicellate. Ascospores 30–45 × 6–7.5 μm (\( \bar{x} \) = 36 × 6.5 μm, n = 50), 2–3-seriate, fusiform, hyaline, slightly curved, tapering toward the ends, enlarged at the 3rd cell, guttulate, 5–6-septate, not constricted at the septa. Asexual morph Hyphomycetous, chlamydosporous. Conidiophores lacking. Chlamydospores 50–90 μm long, 30–45 μm wide (\( \bar{x} \) = 67 × 35 μm, n = 20), holoblastic, sometimes intercalary, broadly oval to ellipsoid, dictyoseptate, pale brown when immature, darkened to black when matured, with terminal cells round and subhyaline.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing slowly on malt extract agar (MEA), circular, with flat surface, veined and without wrinkle, edge entire, reaching 31 mm in 4 weeks at 28 °C, brown to dark brown in MEA media. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, becoming dark brown due to the development of chlamydospores (Fig. 7).

Material examined: THAILAND, Krabi, Plai Praya, Khao To, Ban Bang Thao Mae, on submerged decaying wood in a freshwater stream, 17 December 2015, Saranyaphat Boonmee, BTM01–2 (MFLU 17–1177, holotype; HKAS 100730, isotype), ex-type living cultures, MFLUCC 16–1130, TBRC.

Notes: Morphologically, Chlamydotubeufia cylindrica differs from C. krabiensis by its shorter but larger ascomata diameter (175–225 × 175–250 μm vs. 232–261 × 174–207 μm) and differs from C. huaikangplaensis by its longer, but narrower asci (90–110 × 15–18 μm vs. 50–83 × 16–21 μm). Its asexual morphs are hyphomycetous, chlamydosporous, obtained from sexual morph’s living cultures. The multi-gene phylogenetic analysis shows that C. cylindrica formed is basal to C. krabiensis, C. chlamydosporum and the type species C. huaikangplaensis and phylogenetically distinct with good bootstrap support (Fig. 2), which confirmed that C. cylindrica is a new species.

Other accepted Chlamydotubeufia species


Chlamydotubeufia chlamydospora (Shearer) Boonmee & K.D. Hyde [as ‘chlamydosporum’], Fungal Diversity 51: 83 (2011)

≡ Helicoma chlamydosporum Shearer, Mycologia 79(3): 468 (1987)

Index Fungorum: IF 563503

Possible distribution: Italy, Panama.

Habitat: Aquatic.

Notes: This taxon was introduced as Helicoma chlamydosporum by Shearer (1987). Boonmee et al. (2011) synonymized it under Chlamydotubeufia chlamydospora based on phylogenetic evidence. Chlamydotubeufia chlamydospora forms chlamydosporous asexual morph in decaying twig, and both chlamydosporous and helicosporous asexual morph were found from its single chlamydospore isolates (Shearer 1987).


Chlamydotubeufia depressispora (Matsush.) Boonmee & K.D. Hyde, Fungal Diversity 51: 83 (2011)

≡ Helicoma depressispora Matsush., Matsush. Mycol. Mem. 7: 52 (1993)

Index Fungorum: IF 563504

Possible distribution: Ecuador, Peru.

Habitat: Terrestrial.

Notes: This taxon was introduced as Helicoma depressispora by Matsushima (1993). It is characterized by helicosporous asexual morph in decaying wood and chlamydosporous asexual morph produced from its helicoid conidial cultures (Matsushima 1993). Boonmee et al. (2011) synonymized this taxon under Chlamydotubeufia depressispora based on its morphology resembles C. chlamydospora.


Chlamydotubeufia huaikangplaensis Boonmee & K.D. Hyde, Fungal Diversity 51: 78 (2011)

Index Fungorum: IF 563501

Known distribution: Thailand.

Habitat: Aquatic, Terrestrial.

Notes: Chlamydotubeufia huaikangplaensis was introduced by Boonmee et al. (2011) and it is the type species of Chlamydotubeufia. Hyde et al. (2017) reported its asexual morph from aquatic habitats.


Chlamydotubeufia krabiensis Y.Z. Lu, Boonmee & K.D. Hyde, Fungal Diversity 87: 116 (2017)

Index Fungorum: IF 552931

Known distribution: Thailand.

Habitat: Aquatic.

Notes: Chlamydotubeufia krabiensis was introduced by Hyde et al. (2017) based on phylogenetic and morphological evidence. Its chlamydosporous asexual morph was found from cultures of single ascospore isolation.


Dematiohelicoma Y.Z. Lu, J.C. Kang & K.D. Hyde, gen. nov

Index Fungorum: IF 554821; Facesoffungi number: FoF 04700

Etymology: “Dematio” referring to dematiaceous helicoid conidia of this genus, “helicoma” referring to this genus was separated from Helicoma.

Saprobic on decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, hairy, black. Mycelium mostly immersed, partly superficial, composed of branched, septate hyphae, brown to dark brown, with a few of brown conidia. Conidiophores macronematous, mononematous, erect, cylindrical, unbranched, septate, arising as lateral branches from creeping hyphae, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, sympodial, integrated, terminal and intercalary, cylindrical, truncate at apex after conidial secession, pale brown to brown, smooth-walled. Conidia acropleurogenous, helicoid, solitary, rounded at apex, tapering gradually towards truncate basal cell, basal cells hyaline or subhyaline, multi-septate, dark brown septa, tightly coiled 2–3 times, not becoming loose in water, brown to dark brown, smooth-walled (Linder 1929; Tubaki 1964; Goos 1986; Castañeda-Ruíz et al. 1998; Zhao et al. 2007).

Type species: Dematiohelicoma pulchrum (R.F. Castañeda & Guarro) Y.Z. Lu & K.D. Hyde

Notes: After examination of a number of helicosporous hyphomycetes morphology and analyses of molecular data, we found that, Helicoma pulchrum and H. perelegans described in previous studies, are morphologically similar to each other, but distinct from other helicosporous species in conidial characteristics (Linder 1929; Tubaki 1964; Goos 1986; Castañeda-Ruíz et al. 1998; Zhao et al. 2007). The conidia of Helicoma pulchrum and H. perelegans are characterized by having hyaline or subhyaline basal cells, tapering gradually towards a truncated base, while the remaining cells are reddish-brown, and their conidial septa are dark brown and obviously darker than the adjacent parts. These morphological characters do not tally with the generic concept of Helicoma and other helicosporous genera. In addition, Helicoma pulchrum (MUCL 39827) is phylogenetically segregated from other genera (Fig. 2, Clade 5). Therefore, we introduce a new genus, Dematiohelicoma, to accommodate these two species. Helicoma pulchrum is synonymized to Dematiohelicoma pulchrum and designated as the type species. Helicoma perelegans is synonymized under Dematiohelicoma perelegans.

New combinations of Dematiohelicoma

Dematiohelicoma perelegans (Thaxt. ex Linder) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicoma perelegans Thaxt. ex Linder, Ann. Mo. bot. Gdn 16: 303 (1929)

Index Fungorum: IF 554822; Facesoffungi number: FoF 04790

Type: USA, Massachusetts, Waverly, on bark of Platanus, Thaxter, FH-No. 838.

Possible distribution: China (Hainan, Hubei, Yunnan), Cuba, Czechia, Japan, Mexico, New Zealand, USA (Massachusetts).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Linder (1929, as Helicoma perelegans), Goos (1986, as H. perelegans) and Zhao et al. (2007, as H. perelegans).

Notes: This taxon was introduced as Helicoma perelegans by Linder (1929). Tubaki (1964) reported a new record of H. perelegans from Japan, and Hughes (1978) reported from New Zealand. Tsui et al. (2006) provided ITS and LSU sequence data for an isolate named “Helicoma perelegans ATCC 22621” but did not describe its morphology. Zhao et al. (2007) reported several new records of H. perelegans and mentioned that their specimens showed morphologically variations such as number of coils, colour and size of conidia, as well as conidiophores shape, but they considered that those differences might be the variations within species. Boonmee et al. (2014) renamed H. perelegans (ATCC 22621) as Tubeufia intermedium (ATCC 22621) in their phylogenetic tree, but did not synonymize it. Later studies also treated this taxon as T. intermedium based on phylogeny (Hyde et al. 2016a; Lu et al. 2017b; Luo et al. 2017). In this study, our phylogenetic analyses showed that H. perelegans (ATCC 22621) group within Tubeufia, but lacked bootstrap support (Figs. 2, 54). Furthermore, its morphology does not fit into the generic concept of Tubeufia, but resembles Dematiohelicoma pulchrum (Castañeda-Ruíz et al. 1998; Zhao et al. 2007, as Helicoma pulchrum) in conidiophores and conidia. Therefore, we refer it under the genus Dematiohelicoma. However, we renamed H. perelegans (ATCC 22621) as Tubeufia sp. and suggest that this isolate needs further taxonomic investigation, as its DNA data are neither obtained from type specimens nor its morphological descriptions are properly illustrated.


Dematiohelicoma pulchrum (R.F. Castañeda & Guarro) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicoma pulchrum R.F. Castañeda & Guarro [as ‘pulchra’], Mycol. Res. 102(1): 58 (1998)

Index Fungorum: IF 554823; Facesoffungi number: FoF 04791

Type: CUBA, Holguin, on decaying bark, R.F. Castañeda, 6 December 1995, INIFAT C96/23-1, holotype; MUCL 39945, isotype.

Possible distribution: Canada, China (Hubei), Cuba, Japan.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Castañeda-Ruíz et al. (1998, as Helicoma pulchrum) and Zhao et al. (2007, as Helicoma pulchrum).

Notes: This taxon was introduced as Helicoma pulchrum by Castañeda-Ruíz et al. (1998). Morphologically, it resembles Dematiohelicoma perelegans (this study) in conidiophores and conidia. Tsui et al. (2006) provided the ITS and LSU sequence data (H. pulchrum MUCL 39827). Zhao et al. (2007) reported a new record of H. pulchrum. Our phylogenetic result shows that H. pulchrum (MUCL 39827) is separated from Helicoma and shares a close relationship to Helicomyces species (Fig. 2), but their morphology are different, therefore, we synonymize this taxon under Dematiohelicoma pulchrum and assigned it as the type species of Dematiohelicoma.


Dematiohelicomyces Y.Z. Lu, Boonmee & K.D. Hyde, gen. nov.

Index Fungorum: IF 554824; Facesoffungi number: FoF 04701

Etymology: “Dematio-” referring to dematiaceous conidiophores of this genus, “-helicomyces” referring to its morphogy similar to Helicomyces.

Saprobic on decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to light pink. Mycelium mostly immersed, partly superficial, composed of branched, septate hyphae, pale brown, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, mostly unbranched, 0–3-septate, pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, pale brown, smooth-walled. Conidia solitary, acrogenous, helicoid, dry, coiled 1½–3¾ times, becoming loosely coiled or uncoiled in water, rounded at tip, multi-septate, guttulate, hyaline, smooth-walled.

Type species: Dematiohelicomyces helicosporus (Boonmee, Y.Z. Lu & K.D. Hyde) Y.Z. Lu

Notes: The new genus Dematiohelicomyces is introduced based on its morphological resemblance to Helicomyces in having short conidiophores that are 0–3-septate, and helicoid conidia, having a spathulate basal end cell, but can be distinguished by its brown conidiophores (Fig. 8). Furthermore, our phylogenetic analyses show that our three isolates of Dematiohelicomyces helicosporus belong to a distinct clade (Clade 13) with good support basal to Helicohyalinum and Helicodochium (Fig. 2).

Fig. 8
figure 8

Dematiohelicomyces helicosporus (MFLU 17–1160). a, b Colony on decaying wood. c Conidiogenous cell with attached conidium. d, e Conidiophores. f, g Colonies on MEA from above and below. h–l Conidia. m Germinating conidium. b, MFLU 17–1161. Scale bars: a, b = 500 µm, c, h–m = 50 µm, d, e = 20 µm

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New combination of Dematiohelicomyces

Dematiohelicomyces helicosporus (Boonmee, Y.Z. Lu & K.D. Hyde) Y.Z. Lu, comb. nov.

≡ Chlamydotubeufia helicospora Boonmee, Y.Z. Lu & K.D. Hyde, Fungal Diversity 80: 123 (2016)

Index Fungorum: IF 554825; Facesoffungi number: FoF 04702; Fig. 8

Type: THAILAND, Uttaradit, Laplae, Mae Phun, Ban Ton Klua, on decaying wood in freshwater stream, 24 October 2015, Saranyaphat Boonmee, MFLU 16–1338.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to light pink. Mycelium mostly immersed, partly superficial, composed of branched, septate hyphae, pale brown, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, erect, cylindrical, mostly unbranched, 0–3-septate, pale brown, arising as lateral branches from creeping hyphae, smooth-walled, 30–50 μm long, 3.5–4.5 μm wide. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, pale brown, smooth-walled, 13–20 μm long, 3.5–4.5 μm wide. Conidia solitary, acrogenous, helicoid, dry, attached eccentrically and seceding schizolytically, rounded at tip, the basal cells broadly spathulate and bearing a flattened attachment scar, guttulate, hyaline, 70–100 μm in diam. and conidial filament 5.5–8 μm wide in the broadest part (\( \bar{x} \) = 80 × 7 μm, n = 20), tapering to 4–5 μm wide near apex and base, 400–600 μm long, 50–60-septate, coiled 1½–2¾ times, becoming loosely coiled or uncoiled in water.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, circular, with flat surface, edge entire, reaching 26 mm in 4 weeks at 28 °C, pale brown to brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Uttaradit, Laplae, Mae Phun, Ban Ton Klua, on decaying wood in a freshwater stream, 24 October 2015, Saranyaphat Boonmee, UTD11 (MFLU 17–1160 = HKAS 100711), living culture, MFLUCC 16–0003; Ibid., UTD12 (MFLU 17–1161 = HKAS 100714), living culture, MFLUCC 16–0007.

Notes: This taxon was introduced as Chlamydotubeufia helicospora by Hyde et al. (2016a). Morphologically, it resembles to Helicomyces torquatus and H. hyalosporus in having short conidiophores with 0–3-septate, and helicoid conidia with a spathulate basal end cell, but can be distinguished by its pale brown conidiophores, and narrower and loose helicoid conidia. Based on morphology and phylogeny, we synonymize this taxon under Dematiohelicomyces helicosporus.


Dematiohelicosporum Y.Z. Lu, J.K. Liu & K.D. Hyde, gen. nov.

Index Fungorum: IF 554826; Facesoffungi number: FoF 04703

Etymology: “Dematiohelicosporum” referring to dematiaceous helicoid conidia of this genus.

Saprobic on decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium mostly immersed, partly superficial, composed of branched, septate hyphae, pale brown to brown, with a few of brown conidia. Conidiophores macronematous, mononematous, erect, cylindrical, mostly unbranched, 0–3-septate, pale brown, arising as lateral branches from creeping hyphae, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, terminal, cylindrical, truncate at apex after conidial secession, brown, smooth-walled. Conidia solitary, acrogenous, helicoid, slightly circinate in three dimensions, rounded at apex, truncate at basal cell, basal cell elongated, tapering to ends, indistinctly multi-septate, coiled 4–5 times, becoming loosely coiled in water, guttulate, olivaceous to brown, smooth-walled.

Type species: Dematiohelicosporum guttulatum Y.Z. Lu, J.K. Liu & K.D. Hyde

Notes: Morphologically, Dematiohelicosporum is similar to Berkleasmium species in conidiophores and conidiogenous cells, but can be distinguished by conidial morphology. The conidia of Dematiohelicosporum are slightly circinate in three dimensions, clearly verrucose and guttulate, olivaceous to brown and these characteristics are distinct to other known helicosporous hyphomycetes. Furthermore, our phylogenetic result shows that Dematiohelicosporum forms a basal clade (Clade 37) distinct from Berkleasmium and Neoacanthostigma, which indicate that Dematiohelicosporum is a distinct genus.


Dematiohelicosporum guttulatum Y.Z. Lu, J.K. Liu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554827; Facesoffungi number: FoF 04704; Fig. 9

Fig. 9
figure 9

Dematiohelicosporum guttulatum (MFLU 17–1152, holotype). a Colony on decaying wood. b–d Conidiophores with attached conidia. e–i Conidiophores and conidiogenous cells. j–n Conidia. o Germinating conidium. p, q Colonies on PDA from above and below. r Umbonate colony surface on PDA from above. Scale bars: a = 100 µm, b–d, j–o = 50 µm, e–i = 20 µm

Full size image

Holotype: MFLU 17–1152

Etymology: “guttulatum” referring to the conidia of this taxon containing many special guttulate.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a forest of mountain. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium mostly immersed, partly superficial, composed of branched, septate hyphae, pale brown to brown, with a few of brown conidia. Conidiophores macronematous, mononematous, erect, cylindrical, mostly unbranched, 0–3-septate, arising as lateral branches from creeping hyphae, 10–45 μm long, 3–4.5 μm wide, pale brown, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, terminal, cylindrical, truncate at apex after conidial secession, 9–20 μm long, 3.5–4.5 μm wide, brown, smooth-walled. Conidia solitary, acrogenous, helicoid, slightly circinate in three dimensions, rounded at apex, truncate at basal cell, basal cell elongated, 30–40 μm long, 4–5 μm wide, 65–80 μm in diam. and conidial filament 8–10 μm wide in the broadest part (\( \bar{x} \) = 73 × 9 μm, n = 20), tapering to 4–4.5 μm wide near apex and base, 650–840 μm long, indistinctly multi-septate, coiled 4–5 times, becoming loosely coiled in water, guttulate, olivaceous to brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 36 h. Colonies growing on PDA, circular, with umbonate surface, without wrinkle, edge entire, reaching 10 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on decaying wood in a mountain, 26 April 2017, Yong-Zhong Lu, TM05 (MFLU 17–1152, holotype; HKAS 100823, isotype), ex-type living cultures, MFLUCC 17–2011, TBRC.

Notes: Morphologically, Dematiohelicosporum guttulatum is similar to Berkleasmium species in having short, 0–3-septate conidiophores, arising as lateral branches from creeping hyphae, and conidiogenous cells that are terminal, cylindrical and truncate at the apex after conidial secession, but clearly distinguished by conidia that are slightly circinate in three dimensions, obviously verrucose and guttulate and olivaceous to brown.


Dematiotubeufia Y.Z. Lu, Boonmee & K.D. Hyde, gen. nov

Index Fungorum: IF 554828; Facesoffungi number: FoF 04705

Etymology: “Dematio-” referring to dematiaceous ascomata of this genus, “-tubeufia” referring to the type genus (Tubeufia) of Tubeufiaceae.

Saprobic on decaying wood. Sexual morph Ascomata superficial, solitary, scattered, oval to subglobose, seated on a subiculum, dark brown to black, with a central ostiole. Ostiole single, central, with white velvety appendix. Peridium composed of cells of textura angularis, with inner cells brown and outer cells dark brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores biseriate, cylindric to fusiform, tapering towards rounded ends, straight to slightly curved, guttulate, multi-septate, hyaline, smooth-walled. Asexual morph Undetermined.

Type species: Dematiotubeufia chiangraiensis (Boonmee & K.D. Hyde) Y.Z. Lu

Notes: Our phylogenetic result shows that the isolate MFLUCC 10–0115 forms a distinct clade (Clade 30) sharing a close relationship to Kamalomyces, Helicoarctatus and Neohelicoma (Figs. 2, 15). Additionally, its morphology can be easily distinguished from other genera by its dark brown to black, shiny ascomata with distinct ostioles (Boonmee et al. 2014), therefore, Dematiotubeufia gen. nov. is introduced in this study to accommodate this taxon.

New combinations of Dematiotubeufia

Dematiotubeufia chiangraiensis (Boonmee & K.D. Hyde) Y.Z. Lu, comb. nov.

≡ Helicoma chiangraiense Boonmee & K.D. Hyde, Fungal Diversity 68: 271 (2014)

Index Fungorum: IF 554829; Facesoffungi number: FoF 04792

Type: THAILAND, Chiang Rai, Muang, Doi Pui, on dead wood of Fagaceae, 15 August 2009, Saranyaphat Boonmee, MFLU 10–0048 (holotype), PDD 104455 (isotype); ex-type living cultures, MFLUCC 10–0115 = BCC 39624.

Known distribution: Thailand.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Boonmee et al. (2014, as Helicoma chiangraiense).

Notes: This taxon was introduced as Helicoma chiangraiense by Boonmee et al. (2014) based on its morphological differences from other Helicoma species in having dark brown to black, shiny, non setose ascomata, and distinct ostioles with white velvety appendix. Our multi-gene phylogeny tree shows that this taxon is phylogenetically apart from Helicoma species and is nested in between Helicoma, Helicoarctatus, Kamalomyces and Neohelicoma (Fig. 15). Therefore, we synonymize it as Dematiotubeufia chiangraiensis.


Dictyospora Brahaman., Y.Z. Lu, Boonmee & K.D. Hyde, Mycosphere 8(7): 924 (2017)

Index Fungorum: IF 553178

Saprobic on decaying wood. Sexual morph Ascomata superficial, solitary or scattered, globose to subglobose, black, setose, coriaceous, with a central ostiole. Ostiole single, central. Setae covering the whole ascoma, dark brown to black, taper to an acute apex, unbranched, thick-walled. Peridium composed of several layers of cells of textura angularis. Hamathecium branched pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, cylindrical to clavate or saccate, apically rounded, short pedicellate. Ascospores fasciculate, fusiform, hyaline, slightly curved, tapering toward the ends, guttulate, 5–6-septate, not constricted at the septa. Asexual morph Hyphomycetous, chlamydosporous. Conidiophores lacking. Chlamydospores holoblastic, sometimes intercalary, broadly oval to ellipsoid, dictyoseptate, pale brown when immature, darkened to black when matured.

Type species: Dictyospora thailandica Brahaman., Y.Z. Lu, Boonmee & K.D. Hyde, Mycosphere 8(7): 924 (2017)

Notes: The genus Dictyospora was introduced by Brahamanage et al. (2017) and characterized by superficial ascomata covered by dark brown to black setae, bitunicate asci and slightly curved fusiform ascospores, with a chlamydosporous asexual morph. Dictyospora resembles Chlamydotubeufia in both asexual and sexual morphs, but phylogenetic analyses indicate that they are distinct genera (Clade 34). In this paper, we describe a new isolate of Dictyospora thailandica bearing some peculiar morphological characteristics.


Dictyospora thailandica Brahaman., Y.Z. Lu, Boonmee & K.D. Hyde, Mycosphere 8(7): 924 (2017)

Index Fungorum: IF 553179; Facesoffungi number: FoF 03263; Figs. 10 and 11

Fig. 10
figure 10

The sexual morph of Dictyospora thailandica (MFLU 17–1179). a, b Superficial ascomata on substrate. Note ascomata surrounded by brown to black setae. c Peridium. d Ascoma. e Seta. f–h Asci. j–m Ascospores. m, n Colonies on PDA from above and below. Scale bars: a, b = 200 µm, c, e–m = 20 µm, d = 100 µm

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Fig. 11
figure 11

The asexual morph of Dictyospora thailandica (from cultures of MFLU 17–1179). a Hyphae in PDA. b–j Conidiogenous cells with attached chlamydospores. Scale bars: a–j = 50 µm

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Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Ascomata 200–260 μm high × 200–270 μm diameter (\( \bar{x} \) = 230 × 240 μm, n = 10), superficial, solitary or scattered, globose to subglobose, black, setose, coriaceous, with a central ostiole. Ostiole single, central. Setae 50–70 × 4–5 μm, covering the whole ascoma, dark brown to black, tapering to an acute apex, unbranched, thick-walled. Peridium 20–30 μm thick, composed of several layers of cells of textura angularis. Hamathecium of 1–2 μm wide, branched pseudoparaphyses. Asci 90–110 × 14–17 μm (\( \bar{x} \) = 100 × 15 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical to clavate or saccate, apically rounded, short pedicellate. Ascospores (29–) 40–50 (–57) × 5–7 μm (\( \bar{x} \) = 46 × 6 μm, n = 50), fasciculate, fusiform, hyaline, slightly curved, tapering toward the ends, enlarged at the 3rd cell, guttulate, 5–6-septate, not constricted at the septa. Asexual morph Hyphomycetous, chlamydosporous. Conidiophores lacking. Chlamydospores 70–105 μm long, 45–60 μm wide (\( \bar{x} \) = 85 × 50 μm, n = 20), holoblastic, sometimes intercalary, broadly oval to ellipsoid, dictyoseptate, pale brown when immature, darkened to black when matured.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing on PDA, irregular, with flat surface, edge undulate, reaching 23 mm in 4 weeks at 28 °C, brown to dark brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, becoming dark brown due to the development of chlamydospores (Fig. 11).

Material examined: THAILAND, Krabi, Plai Praya, Khao To, Ban Bang Thao Mae, on submerged decaying wood in a freshwater stream, 17 December 2015, Saranyaphat Boonmee, BTM03 (MFLU 17–1179), living culture, MFLUCC 18–0641.

Notes: Our new isolate MFLU 17–1179 is morphologically most similar to Chlamydotubeufia cylindrica, but clusters together with Dictyospora thailandica with good bootstrap support (100% MLBS, 1.00 PP) (Fig. 2). There are only 4 and 3 base pairs differences in ITS and TEF1α sequence data between our new isolate and the type strain of D. thailandica (MFLUCC 16–0001), and no differences in LSU and RPB2 sequence data, which indicated that they are the same species. Our isolate has also been collected from submerged decaying wood in an aquatic habitat similar to other isolates. It is necessary to point out that our new isolate is different to previously described D. thailandica isolates by its larger ascomata (200–260 × 200–270 μm vs. 173–212 × 165–206 μm) and smaller asci (90–110 × 14–17 μm vs. 129–182 × 18–24.5 μm) as well as the shorter ascospores (40–50 μm vs. 76–107 μm) (Brahamanage et al. 2017), but their asexual morphs are identical.


Helicoarctatus Y.Z. Lu, J.C. Kang & K.D. Hyde, gen. nov.

Index Fungorum: IF 554830; Facesoffungi number: FoF 04707

Etymology: “Helicoarctatus” referring to tightly helicoid conidia.

Saprobic on submerged decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, brown to dark brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, setiform, cylindrical, unbranched, septate, tapering towards apex, brown to dark brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, determinate, discrete, denticulate, arising laterally from lower portion of the conidiophores as tiny tooth-like protrusions, with each bearing 1–2 tiny sporogenous conidiogenous loci, hyaline, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, multi-septate, tightly coiled 3–4 times, will not becoming loosely in water, guttulate, hyaline, smooth-walled.

Type species: Helicoarctatus aquaticus Y.Z. Lu, J.C. Kang & K.D. Hyde

Notes: Morphologically, Helicoarctatus shares similar morphology to Helicosporium in having setiform conidiophores, and discrete, tooth-like protrusions conidiogenous cells arising laterally from lower portion of the conidiophores, with each bearing 1–2 tiny sporogenous conidiogenous loci. Helicoarctatus can be distinguished from Helicosporium by its larger conidia. The conidiogenous cells of Helicoarctatus are conspicuous from Helicoma, Helicomyces, Neohelicomyces, Neohelicosporium and Tubeufia, which are previously described helicosporous genera in Tubeufiaceae. Phylogenetically, Helicoarctatus shares a sister relationship to Neohelicoma (Figs. 2, 15). As Neohelicoma fagacearum is a sexual morph species while Helicoarctatus aquaticus is an asexual morph species, we could not compare their morphology. However, our phylogenetic result shows that Helicoarctatus and Neohelicoma are distinct genera (Figs. 2, 15).


Helicoarctatus aquaticus Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554831; Facesoffungi number: FoF 04708; Fig. 12

Fig. 12
figure 12

Helicoarctatus aquaticus (MFLU 17–1136, holotype). a, b Colony on decaying wood. c–e Conidiophores. f–h Conidiogenous cells. i–m Conidia. n Germinating conidium. o, p Colonies on PDA from above and below. q Umbonate colony surface on PDA from above. Scale bars: a–e = 100 µm, f–n = 20 µm

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Holotype: MFLU 17–1136

Etymology: “aquaticus” referring to aquatic habitat of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, brown to dark brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, setiform, cylindrical, unbranched, septate, 195–405 μm long, 5–11 μm wide at bottom, tapering to 2–3 μm wide at apex, brown to dark brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, determinate, discrete, denticulate, arising laterally from lower portion of the conidiophores as tiny tooth-like protrusions (3–7.5 μm long, 1.5–3.5 μm wide), with each bearing 1–2 tiny sporogenous conidiogenous loci, hyaline, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 27–38 μm diam. and conidial filament 4–5 μm wide (\( \bar{x} \) = 33 × 4.5 μm, n = 20), 185–255 μm long, 16–20-septate, tightly coiled 3–4 times, will not becoming loosely in water, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with a center slight umbonate surface, edge entire, reaching 26 mm in 3 weeks at 28 °C, pale brown to brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW06–1 (MFLU 17–1136, holotype; HKAS 100807, isotype), ex-type living cultures, MFLUCC 17–1996, TBRC.

Notes: Helicoarctatus aquaticus forms a helicosporous asexual morph on the natural decaying woody substrate and is morphologically similar to Helicosporium species as conidiophores are setiform, conidiogenous cells are discrete, arising laterally from lower portion of the conidiophores as tiny tooth-like protrusions, with each bearing 1–2 tiny sporogenous conidiogenous loci. However, H. aquaticus differs from Helicosporium species by its larger conidia. Phylogenetically, H. aquaticus shares a close relationship to Neohelicoma fagacearum (Figs. 2, 15).


Helicodochium J.S. Monteiro, R.F. Castañeda, A.C. Cruz & Gusmão, Mycotaxon 127: 6 (2014)

Index Fungorum: IF 804995

Saprobic on submerged decaying woody substrates. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the natural substrate effuse, pinkish to pink. Mycelium partly immersed, partly superficial. Conidiomata sporodochial, apothecium-like, dry, scattered, pinkish to pink, consisting of numerous conidiophores arising from a stroma of globose, thick-walled, pale brown cells. Conidiophores macronematous, erect, branched or unbranched, septate, arising from a thick-walled, pseudoparenchymatous stromata with globose texture, pale brown, smooth-walled. Conidiogenous cells monoblastic, integrated, terminal, pale brown to hyaline, smooth-walled. Conidia solitary, acrogenous, helicoid, rounded at ends, multi-septate, forming a compact, incurved cluster towards the centre of the conidiomata, hyaline to pink, smooth-walled.

Type species: Helicodochium amazonicum J.S. Monteiro, R.F. Castañeda, A.C. Cruz & Gusmão, Mycotaxon 127: 6 (2014)

Notes: The genus Helicodochium was introduced by Monteiro et al. (2014) and is characterized by sporodochial conidiomata, macronematous branched conidiophores, and conidiogenous cells that produce helicoid multiseptate smooth hyaline conidia. Wijayawardene et al. (2017a, b) referred this genus to Ascomycota genera incertae sedis. In this study, we describe a novel Helicodochium species, H. aquaticum, as a second Helicodochium species, and accept Helicodochium as a genus of Tubeufiaceae based on morphological and phylogenetic evidence. Our multi-gene phylogenetic analysis shows that the genus Helicodochium (Clade 11) shares a sister relationship to the genus Helicohyalinum with good bootstrap support (96% MLBS, 1.00 PP) (Fig. 2).


Helicodochium aquaticum Y.Z. Lu, Boonmee & K.D. Hyde, sp. nov.

Index Fungorum: IF 554832; Facesoffungi number: FoF 04709; Fig. 13

Fig. 13
figure 13

Helicodochium aquaticum (MFLU 17–1094, holotype). a–d Colony on decaying wood. e Conidiophores with attached conidia. f Conidiophores with conidiogenous cells. g–k Conidia. l, m Colony on MEA from above and below. n Umbonate and wrinkled colony surface on MEA from above. Notes d, e, g, i, k MFLU 17–1157. Scale bars: a–d = 200 µm, e, f, i–k = 20 µm, g, h = 50 µm

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Holotype: MFLU 17–1094

Etymology: “aquaticum” referring to aquatic habitat of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, pink. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia, forming a sporodochial conidiomata. Conidiomata sporodochial, apothecium-like, superficial, mostly in groups, sometimes scattered, pinkish to pink, glistening. Conidiophores macronematous, mononematous, cylindrical, erect, 1–3-septate, arising from subglobose stromatic cells (5–8 μm long, 4–7 μm wide), 10–25 μm long, 4–5.5 μm wide, pale brown at base, hyaline towards apex, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, terminal, cylindrical, truncate or round at apex after conidial secession, 6–13 μm long, 4–5.5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acrogenous, helicoid, guttulate, rounded at tip, 42–60 μm diam. and conidial filament 5–7 μm wide (\( \bar{x} \) = 50 × 6 μm, n = 20), 620–730 μm long, multi-septate, tightly coiled 5–8 times, not becoming loose in water, forming a compact, incurved cluster towards the centre of the conidiomata, guttulate, hyaline to pink, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, circular, obviously umbonate, with rough surface, veined and wrinkle, edge entire, reaching 7 mm in 3 weeks at 28 °C, brown to dark brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR12 (MFLU 17–1094, holotype; HKAS 100764, isotype), ex-type living cultures, MFLUCC 17–2016, TBRC 8911; Ibid., CR18 (MFLU 17–1101 = HKAS 100771, paratype), living culture, MFLUCC 18–0490; THAILAND, Uttaradit, Laplae, Mae Phun, Ban Ton Klua, on decaying wood in a freshwater stream, 24 October 2015, Saranyaphat Boonmee, UTD05–1 (MFLU 17–1157 = HKAS 100708, paratype), living culture, MFLUCC 16–0008.

Notes: Helicodochium aquaticum is morphologically similar to Helicodochium amazonicum in having pink, glistening conidia forming a sporodochial conidiomata on woody substrates and conidiophores arising from subglobose stromatic cells. However, H. aquaticum is distinct from H. amazonicum in having a smaller helicoid conidial diameter (42–60 vs. 70–82.5 μm diam.) and longer conidial filaments (620–730 vs. 112.5–145 μm long). Besides, the conidia of H. aquaticum are tightly coiled 5–8 times, does not become loose in water, while those of H. amazonicum are loosely coiled 1½–2 times. Phylogenetically, our three new isolates formed a distinct clade with high bootstrap support (Fig. 2) and the topology shows that it is a distinct species to other known species.


Helicohyalinum Y.Z. Lu, J.K. Liu & K.D. Hyde, gen. nov.

Index Fungorum: IF 554833; Facesoffungi number: FoF 04710

Etymology: “Helicohyalinum” referring to hyaline helicoid conidia and conidiophores of this genus.

Saprobic on submerged decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, hyaline to white. Mycelium composed of partly immersed, partly superficial, septate, hyaline, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, unbranched or branched, 0–3-septate, the terminal cell tapering towards apex, inverted funnel at apex, hyaline, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, terminal, cylindrical, tapering towards apex, inverted funnel at apex, hyaline, smooth-walled. Conidia solitary, acrogenous, helicoid, rounded at tip, guttulate, multi-septate, tightly coiled 2½–3½ times, not becoming loose in water, easily deforming and fracturing, hyaline, smooth-walled.

Type species: Helicohyalinum infundibulum Y.Z. Lu, J.K. Liu & K.D. Hyde

Notes: Morphologically, the genus Helicohyalinum can be distinguished from other helicosporous genera by its flexuous, cylindrical, 0–3-septate, hyaline conidiophores with the terminal conidiogenous cells tapering towards apex, having an inverted funnel shape at apex. Phylogenetically, Helicohyalinum (Clade 12) shares a sister relationship to the genus Helicodochium with high bootstrap support (96% MLBS, 1.00 PP) (Fig. 2). However, its morphology differs from Helicodochium in conidiophores and conidiogenous cells, as well as the conidia. Therefore, Helicohyalinum gen. nov is introduced here to accommodate Helicohyalinum aquaticum and Helicohyalinum infundibulum.


Helicohyalinum infundibulum Y.Z. Lu, J.K. Liu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554834; Facesoffungi number: FoF 04711; Fig. 14

Fig. 14
figure 14

Helicohyalinum infundibulum (HKAS 100826, holotype). a, b Colony on decaying wood. c Conidiophore with attached conidium. d, e Conidiophores with conidiogenous cells. f–l Conidia. m, n Colony on PDA from above and below. Scale bars: a, b = 200 µm, c–l = 20 µm

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Holotype: HKAS 100826

Etymology: “infundibulum” referring to the inverted funnel shape of conidiogenous cells of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, 0–3-septate, unbranched or branched, cylindrical, 25–40 μm long, 4–5 μm wide, hyaline, smooth-walled. Conidiogenous cells integrated, terminal, cylindrical, tapering towards apex, inverted funnel at apex, 9–24 μm long, 3.5–4.5 μm wide, hyaline, smooth-walled. Conidia solitary, acrogenous, helicoid, hygroscopic, rounded at the tip, 40–50 μm diam. and conidial filament 6.5–8.5 μm wide in the broadest part (\( \bar{x} \) = 44 × 7.5 μm, n = 20), tapering to 3.5–4.5 μm wide near apex and the base, 250–330 μm long, tightly coiled 2½–3½ times, not becoming loose in water, 40–45-septate, soft, easily deforming and fracturing, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, with flat surface, edge undulate, reaching 9 mm in 3 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 28 November 2015, Saranyaphat Boonmee and Yong-Zhong Lu, TUB03–5 (HKAS 100826, holotype), ex-type living cultures, MFLUCC 16–1133, TBRC 8910.

Notes: Morphologically, Helicohyalinum infundibulum resembles Helicohyalinum aquaticum in having short conidiophores and terminal monoblastic conidiogenous cells with an inverted funnel shape, but can be distinguished by its conidia features. The conidia of H. infundibulum are tightly coiled 2½–3½ times that are not loose in water, but the conidia of H. aquaticum become loosely coiled or uncoiled in water. Besides, the conidia of H. infundibulum are smaller in size than H. aquaticum (40–50 μm vs. 62–89 μm diam.). Phylogenetically, H. infundibulum shares a sister relationship to H. aquaticum with high bootstrap support (100% MLBS, 1.00 PP) (Fig. 2), and the topology of our phylogenetic tree shows that they are distinct species.

New combination of Helicohyalinum

Helicohyalinum aquaticum (Brahaman., Y.Z. Lu, Boonmee & K.D. Hyde) J.K. Liu, comb. nov.

≡ Chlamydotubeufia aquatica Brahaman., Y.Z. Lu, Boonmee & K.D. Hyde, Mycosphere 8 (7): 922 (2017)

Index Fungorum: IF 554835

Type: THAILAND, Krabi, Plai Praya, Khao To, Ban Bang Thao Mae, on submerged decaying wood, 17 December 2015, S. Boonmee, MFLU 17–0501.

Known distribution: Thailand

Habitat: Aquatic.

Description: For a complete description of this taxon see Brahamanage et al. (2017, as Chlamydotubeufia aquatica).

Material examined: THAILAND, Prachuap Khiri Khan, Bang Sapan, Ron Thai, on decaying wood in flowing freshwater stream, 30 July 2015, K.D. Hyde, TF05 (HKAS 100720), living culture, MFLUCC 16–0014.

Notes: Helicohyalinum aquaticum was introduced by Brahamanage et al. (2017) as Chlamydotubeufia aquatica. We synonymize it under the genus Helicohyalinum based on phylogenetic and morphological evidence. Phylogenetically, this species shares a sister relationship to Helicohyalinum infundibulum with high bootstrap support (100% MLBS, 1.00 PP) (Fig. 2). Morphologically, this species shares similar characteristics to H. infundibulum, but is distinct from Chlamydotubeufia species as its conidiophores are flexuous, cylindrical, unbranched, 0–3-septate, hyaline, and conidiogenous cells are cylindrical, tapering towards apex, inverted funnel at apex, hyaline, and conidia are acrogenous and helicoid. A new isolate of H. aquaticum was collected from a fresh water in Thailand, and its morphology and molecular data are identical to the holotype of this species.


Helicoma Corda, Icon. fung. (Prague) 1: 15 (1837)

Index Fungorum: IF 8473

Saprobic on woody substrata. Mycelium partly immersed, septate, branched hyphae. Sexual morph Ascomata superficial, seated on a subiculum, solitary, scattered, subglobose, oval to oboviod, with soft texture, dark brown, with a central ostiole, rarely with setae. Ostiole single, papillate, central. Peridium thick-walled, composed of cells of textura angularis, with inner cells brown and outer cells dark brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, short-pedicellate, apically rounded. Ascospores 2–3-seriate, fusiform to clavate, tapering towards rounded ends, straight or slightly curved, multi-septate, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Conidiophores macronematous, mononematous, erect, cylindrical, branched or unbranched, septate, pale brown to dark brown, smooth-walled. (1) Conidiogenous cells holoblastic, monoblastic, integrated, sympodial, intercalary and/or terminal, cylindrical, with tiny denticles, hyaline to brown, smooth-walled. Conidia solitary, acrogenous, or acropleurogenous, helicoid, circinate, dry, non-hygroscopic, tapering towards apex, truncate at base, coiled 1¼–1¾ times, not becoming loose in water, multi-septate, hyaline to pale brown; (2) Conidiogenous cells holoblastic, monoblastic, integrated, intercalary, cylindrical, with denticles arising laterally from the lower portion of conidiophores as tooth-like protrusions, hyaline to brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, hygroscopic, tapering towards apex, rounded at tip, coiled 1½–5 times, becoming loosely coiled in water, multi-septate, hyaline to pale brown, smooth-walled.

Type species: Helicoma muelleri Corda, Icon. fung. (Prague) 1: 15 (1837)

Notes: The genus Helicoma was introduced by Corda (1837) based on the type species H. muelleri. It is one of the earliest described helicosporous genera (Morgan 1892; Linder 1929; Moore 1955; Pirozynski 1972; Goos 1986; Zhao et al. 2007). Most of Helicoma species were reported as helicosporous hyphomycetes and most of them lack molecular data (Morgan 1892; Linder 1929; Moore 1955; Pirozynski 1972; Goos 1986; Zhao et al. 2007; Boonmee et al. 2014). Seven sexual species were introduced based on molecular evidence (Boonmee et al. 2014). The sexual-asexual connection of H. khunkornense, H. inthanonense, H. rugosum and H. siamense have been reported by Boonmee et al. (2014). Currently, Index Fungorum (2018) listed 80 records within Helicoma, but many of them are unlikely.

In this study, we redefined the morphological concept of the genus Helicoma to include two additional asexual morphs recovered in our study. One is the previously described typical-Helicoma morphology with conidia that are acrogenous, or acropleurogenous, helicoid, circinate, dry, tapering towards apex, truncate at the base, coiled 1¼–1¾ times, not becoming loose in water. Most of these species lack molecular data. However, asexual morphs of our new Helicoma species herein are distinct to these old taxa in form of the conidiogenous cells and conidia, but their placement is strongly supported with phylogenetic evidence. Hence, we identify them as Helicoma species, but refine the concept. Species herein are characterized by conidiogenous cells that are intercalary, cylindrical, with denticles, arising laterally from the lower portion of conidiophores as tooth-like protrusions, and conidia are pleurogenous, helicoid, hygroscopic, tapering towards apex and rounded at tip, coiled 1½–5 times, becoming loosely coiled in water. Their conidial sizes are obviously larger than the previous taxa. Considering the previously described helicosporous hyphomycetes, we introduce ten new Helicoma species (included one sexual morph) and seven new combinations. Helicoma conicodentatum is synonymized under Helicoma ambiens. We accept 57 species within Helicoma including our new species and new combinations, and exclude twelve species from this genus (shown in Table 3).


Helicoma ambiens Morgan, J. Cincinnati Soc. Nat. Hist. 15: 46 (1892)

≡ Helicosporium ambiens (Morgan) Sacc., Syll. fung. (Abellini) 11: 639 (1895)

= Helicoma interveniens P.H.B. Talbot, Bothalia 6: 492 (1956)

= Helicoma conicodentatum Linder, Ann. Mo. bot. Gdn 16: 311 (1929)

Index Fungorum: IF 245979

Possible distribution: Canada (Ontario), China (Liaoning), Cuba, Grenada, South Africa, Tanzania, Trinidad, USA (Hawaii, Iowa, Ohio).

Habitat: Terrestrial.

Notes: Linder (1931) pointed out that Helicoma ambiens was very similar to H. muelleri. Pirozynski (1972) confirmed these two species were distinguishable based on the shape of the conidial basal cell. In H. ambiens, it is rounded, with a characteristic U-shape, while in H. muelleri, the basal cell is more or less V-shaped. Goos (1986) accepted Pirozynski’s treatment. Tsui et al. (2006) provided ITS and LSU sequence data for this species (UAMH 10533) and Zhao et al. (2007) introduced a new record of H. ambiens from China.

In addition, Linder (1929) described the species Helicoma conicodentatum which was accepted by Moor (1986). Tsui et al. (2006) identified a new collection as H. conicodentatum and provided its ITS and LSU sequence data (UAMH 10534). Their phylogenetic analyses showed that H. conicodentatum (UAMH 10534) was identical to H. ambiens (UAMH 10533), but they also mentioned that the conidia and conidiophores of H. conicodentatum and H. ambiens were different in shape and size. Our multi-gene phylogeny tree clearly shows that H. conicodentatum (UAMH 10534) and H. ambiens (UAMH 10533) should be the same species (Fig. 15). We compared their DNA sequence data of ITS and LSU, and found there were no differences between them. Therefore, we treat H. ambiens and H. conicodentatum as the same species based on their similar morphology and molecular data. H. conicodentatum is synonymized under H. ambiens because of the priority of “H. ambiens” over “H. conicodentatum” (Morgan 1892; Linder 1929).

Fig. 15
figure 15

Phylogram generated from maximum likelihood analysis based on combined ITS, LSU and TEF1α sequence data for species of Helicoma and related genera (with Dictyospora thailandica as outgroup). Fifty-three strains are included in the combined sequence analyses which comprise 2253 characters with gaps (710 characters for ITS, 851 for LSU, 912 for TEF1α). Single gene analyses were also performed and tree topology and clade stability compared. The best scoring RAxML tree with a final likelihood value of − 15864.493145 is presented. RAxML bootstrap support values equal to or greater than 75% are given before the forward slash. Maximum parsimony bootstrap support values equal to or greater than 75% are given after the forward slash. Branches with bayesian posterior probability equal to or higher than 0.95 are in bold. Hyphen (‘-’) indicates a value lower than 75% for RAxML and Maximum parsimony. Newly generated sequences are in bold. Strains isolated from the holotype, epitype, paratype and reference specimens are indicated in with a red superscript H, E, P and R, respectively

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Helicoma aquaticum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554836; Facesoffungi number: FoF 04712; Fig. 16

Fig. 16
figure 16

Helicoma aquaticum (MFLU 17–1214, holotype). a, b Colony on decaying wood. c–f Conidiophores. g, h Conidiophores with attached conidia. i, j Conidiogenous cells. k–n Conidia. o, p Colonies on PDA from above and below. Scale bars: a, b = 100 µm, c–h = 50 µm, i, j = 10 µm, k–n = 20 µm

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Holotype: MFLU 17–1214

Etymology: “aquaticum” referring to aquatic habitat of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with a little of glistening conidia. Conidiophores macronematous, mononematous, cylindrical, erect, straight, unbranched, septate, 70–145 μm long, 5–7 μm wide, the lower part brown and the upper part pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, intercalary, cylindrical, 9–14 μm long, 5–6.5 μm wide, with denticles, arising laterally from the lower portion of conidiophores as tiny tooth-like protrusions (1.5–2.9 μm long, 1.2–1.8 μm wide), brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, tapering towards apex, rounded at tip, 33–40 μm diam. and conidial filament 3.5–5 μm wide (\( \bar{x} \) = 36 × 4 μm, n = 20), 220–320 μm long, 23–29-septate, constricted at septa, coiled 2–3½ times, becoming loosely coiled or uncoiled in water, hyaline to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge undulate, reaching 34 mm in 4 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 25 March 2017, Yong-Zhong Lu, CR44 (MFLU 17–1214, holotype; HKAS 100780, isotype), ex-type living cultures, MFLUCC 17–2025, TBRC.

Notes: Helicoma aquaticum is morphologically similar to H. gigasporum (Tsui et al. 2001, as Helicosporium gigasporum) in having conidiophores that are unbranched, the lower part brown and upper part hyaline, conidiogenous cells that are integrated, intercalary, arising laterally from the lower portion of conidiophores as tiny tooth-like protrusions and conidia that are constricted at the septa, but differ in the size of conidiophores and conidia. The conidiophores of H. aquaticum are shorter than H. gigasporum (70–145 vs. 170–250 μm long) and its conidia are also smaller (33–40 μm diam., 3.5–5 μm wide vs. 70–80 μm diam., 6–7 μm wide). Our phylogeny indicates that H. aquaticum is a distinct species and related to H. rufum and H. nematosporum (Fig. 15).


Helicoma brunneisporum Y.Z. Lu, J.K. Liu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554837; Facesoffungi number: FoF 04713; Fig. 17

Fig. 17
figure 17

Helicoma brunneisporum (MFLU 17–1125, holotype). a Colony on decaying wood. b, c Conidiophores with attached conidia. d Conidiophores. e, f Conidiogenous cells. g–l Conidia. m Germinating conidium. n, o Colonies on PDA from above and below. Scale bars: a = 100 µm, b–d, g–m = 50 µm, e, f = 10 µm

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Holotype: MFLU 17–1125

Etymology: “brunneisporum” referring to the brown helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a dry stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with a little of glistening conidia. Conidiophores macronematous, mononematous, cylindrical, erect, straight to slightly bent, unbranched, septate, 90–140 μm long, 7–8.5 μm wide, the lower part brown and the upper part pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, intercalary, cylindrical, 12–14 μm long, 6–8 μm wide, with denticles, arising laterally from the lower portion of conidiophores as tiny tooth-like protrusions (3.4–5.5 μm long, 2.5–3.1 μm wide), brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 55–70 μm diam. and conidial filament 9–14 μm wide in the broadest part (\( \bar{x} \) = 62 × 11 μm, n = 20), tapering to 4–5 μm wide near the apex, 5–6 μm wide at the base, 305–405 μm long, 28–30-septate, slightly constricted at septa, coiled 2¼–3½ times, not becoming loose in water, brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge undulate, reaching 22 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on decaying wood in a dry stream, 27 April 2017, Yong-Zhong Lu, TD09 (MFLU 17–1125, holotype; HKAS 100795, isotype), ex-type living culture, MFLUCC 17–1983.

Notes: Helicoma brunneisporum resembles H. cocois (Matsushima 1971, as Helicosporium serpentinum) in conidiophores, conidiogenous cells and conidia, but can be distinguished by its wider conidiophores (7–8.5 μm vs. 5–6.5 μm) and larger conidial diameter (55–70 μm vs. 40–50 μm) as well as wider conidial filaments (9–14 μm vs. 8–9 μm). Moreover, H. brunneisporum is similar to H. acrophalerium (Moore 1957; Goos 1986) in conidia but can be distinguished by their conidiophores and conidiogenous cells. The conidiophores of H. brunneisporum are cylindrical, the lower part brown and the upper part pale brown, 90–140 μm long, 7–8.5 μm wide, while the conidiophores of H. acrophalerium are fuscous with hyaline inflated terminal cell, up to 10–15 μm long. The conidiogenous cells of H. brunneisporum are mono- to polyblastic, with pleurogenous denticles, but the conidiogenous cells of H. acrophalerium are monoblastic and acropleurogenous (Moore 1957; Goos 1986). Phylogenetically, H. brunneisporum shares a sister relationship to H. septoconstrictum with good bootstrap support (Fig. 15), but phylogenetically it can be considered as a distinct species.


Helicoma cocois Y.Z. Lu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554838; Facesoffungi number: FoF 04793

Type: NEW GUINEA, Papua, Rabaul, on a rotten Cocos nucifera petiole, 8 January 1970, MFC-2918.

Etymology: “cocois” referring to the host genus Cocos on which the type specimen was collected.

Known distribution: New Guinea.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Matsushima (1971, as Helicosporium serpentinum).

Notes: This taxon was introduced as Helicosporium serpentinum by Matsushima (1971). However, we compared its original descriptions to the type of H. serpentinum which was described by Linder (1929), and found that these two descriptions were different in conidiophores, conidiogenous cells and conidia, thus, we consider them as different species. Furthermore, its morphology does not tally with the taxonomic concepts of Helicosporium, but fits well within Helicoma and can also be recognized from other Helicoma species and hence, we introduce this taxon as Helicoma cocois sp. nov. Morphologically, H. cocois resembles H. brunneisporum in having same length of conidiophores, and shaped tooth-like conidiogenous cells protrusions, and both conidia are tightly coiled and not becoming loose in water. However, H. cocois can be distinguished from H. brunneisporum by its narrower conidiophores (5–6.5 μm vs. 7–8.5 μm) and smaller conidial diameter (40–50 μm vs. 55–70 μm) as well as narrower conidial filaments (8–9 μm vs. 9–14 μm). The table below summarises the major morphological differences among atypical Helicoma-like species.


Helicoma fusiforme Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554839; Facesoffungi number: FoF 04714; Fig. 18

Fig. 18
figure 18

Helicoma fusiforme (MFLU 17–1123, holotype). a Superficial ascomata on substrate. b, c Ascoma. d Ostiole. e Peridium. f Asci with hamathecium. g, h Asci. i–m Ascospores. n Germinating ascospore. o, p Colonies on PDA from above and below. Scale bars: a = 200 µm, b, c = 100 µm, d–h = 50 µm, i–n = 20 µm

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Holotype: MFLU 17–1123

Etymology: “fusiforme” referring to the fusiform ascospores of this fungus.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a dry stream. Sexual morph Ascomata 210–270 μm high × 250–290 μm diam., superficial, seated on a subiculum, solitary, scattered, globose to subglobose, dark brown, coriaceous, with a central ostiole. Ostiole single, central. Peridium 30–45 μm wide, composed of cells of textura angularis, with inner cells brown and outer cells dark brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 115–145 × 20–30 μm (\( \bar{x} \) = 125 × 26 μm, n = 20), 8-spored, bitunicate, cylindrical, short-pedicellate, apically rounded. Ascospores 60–70 × 7–8.5 μm (\( \bar{x} \) = 65 × 7.5 μm, n = 50), biseriate, fusiform, tapering towards rounded ends, slightly curved, guttulate, 10–11-septate, slightly constricted at septa, hyaline, smooth-walled. Asexual morph Undetermined.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 11 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on decaying wood in a dry stream, 27 April 2017, Yong-Zhong Lu, TD07 (MFLU 17–1123, holotype; HKAS 100793, isotype), ex-type living cultures, MFLUCC 17–1981, TBRC.

Notes: Helicoma fusiforme is morphologically similar to H. siamense in having superficial, globose to subglobose, dark brown ascomata, bitunicate, cylindrical asci and fusiform ascospores. However, H. fusiforme differs from H. siamense by its wider asci (20–30 μm vs. 14–20 μm) and wider ascospores (7–8.5 μm vs. 5–7.5 μm). Phylogenetically, H. fusiforme shares a sister relationship to H. multiseptatum and H. hongkongense, but with no bootstrap support (Fig. 15). We compare their DNA sequences and noted that there are eight noticeable nucleotide differences between H. fusiforme (MFLUCC 17–1981) and H. multiseptatum (GZCC 16–0080), eight and six differences between H. fusiforme (MFLUCC 17–1981) and H. hongkongense (MFLUCC 17–2005) in ITS and TEF1α sequence data respectively (only ITS and TEF1α sequence data are available for H. fusiforme MFLUCC 17–1981), which support them as distinct species.


Helicoma longisporum Y.Z. Lu, J.K. Liu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554840; Facesoffungi number: FoF 04715; Fig. 19

Fig. 19
figure 19

Helicoma longisporum (MFLU 17–1137, holotype). a Colony on decaying wood. b Conidiophore with attached conidium. c–f Conidiophores. g–j Conidiogenous cells. k–n Conidia. o, p Colonies on PDA from above and below. q Umbonate colony surface on PDA from above. Scale bars: a = 100 µm, b–f, k–n = 50 µm, g–j = 20 µm

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Holotype: MFLU 17–1137

Etymology: “longisporum” referring to the long helicoid conidial filaments.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium composed of partly immersed, partly superficial, pale brown to brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, erect, straight, branched or unbranched, septate, 135–210 μm long, 6–10 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, intercalary, cylindrical, 11–17 μm long, 5.5–10 μm wide, with denticles, arising laterally from the lower portion of conidiophores as tiny tooth-like protrusions (4.8–6.4 μm long, 2.9–3.8 μm wide), pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, enlarged and rounded at tip, 70–150 μm diam. and conidial filament 8–11 μm wide in the broadest part (\( \bar{x} \) = 123 × 9 μm, n = 20), tapering to 3.5–4.5 μm wide near the apex and the base, 620–770 μm long, 46–50-septate, slightly constricted at septa, coiled 1½–2½ times, becoming loosely coiled or uncoiled in water, pale brown to brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, obviously umbonate, with rough surface, veined and wrinkle, edge undulate, reaching 37 mm in 3 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW06–2 (MFLU 17–1137, holotype; HKAS 100808, isotype), ex-type living cultures, MFLUCC 17–1997, TBRC; THAILAND, Uttaradit, Laplae, Mae Phun, Ban Ton Klua, on decaying wood in a freshwater stream, 24 October 2015, Saranyaphat Boonmee, UTD02 (MFLU 17–1155, paratype), living culture, MFLUCC 16–0211; Ibid., UTD05–2 (MFLU 17–1158 = HKAS 100709, paratype), living culture, MFLUCC 16–0002; Ibid., UTD15–2 (MFLU 17–1162 = HKAS 100715, isoparatype), living culture, MFLUCC 16–0005.

Notes: Morphologically, Helicoma longisporum resembles H. septoconstrictum in conidiophores, conidiogenous cells and conidia. However, our multi-gene phylogeny shows that four isolates of H. longisporum formed a clade sister to H. khunkornense (Fig. 15) and clearly apart from H. septoconstrictum, which indicate that they should be distinct species. We compared nucleotides of the ex-type strain of H. longisporum (MFLUCC 17–1997) with the ex-type strain of H. septoconstrictum (MFLUCC 17–2001) and note 25 bp (base pair), 8 bp, 82 bp and 43 bp differences in ITS, LSU, RPB2 and TEF1α respectively, which confirms that they are distinct species. Furthermore, we also noted that our four isolates of H. longisporum are phylogenetically slightly divergent from each other. We also looked into pairwise dissimilarities of DNA sequences and noted that there are 1 bp, 8 bp and 4 bp differences in ITS, RPB2 and TEF1α respectively between MFLUCC 17–1997 and MFLUCC 16–0005, and 1 bp, 2 bp, 5 bp and 4 bp differences in ITS, LSU, RPB2 and TEF1α respectively between MFLUCC 17–1997 and MFLUCC 16–0002, which may explain a close phylogenetic relatedness between them and their slight phylogenetic divergence. However, we could not identify any morphological features to separate these four isolates and those fewer gene base pair changes are not enough to indicate they are different species, thus, we identify these four isolates as H. longisporum.


Helicoma multiseptatum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554841; Facesoffungi number: FoF 04716; Fig. 20

Fig. 20
figure 20

Helicoma multiseptatum (HKAS 97437, holotype). a Colony on decaying wood. b–e Conidiophores. f–i Conidiogenous cells. j–l Conidia. m, n Colonies on PDA from above and below. Scale bars: b–e, j–l = 50 µm, f–i = 10 µm

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Holotype: HKAS 97437

Etymology: “multiseptatum” referring to multi-septate helicoid conidia of this fungus.

Known distribution: China (Guangxi).

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, cream white to brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, branched or unbranched, septate, 95–255 μm long, 5–9 μm wide at bottom, tapering to 2–3 μm wide at apex, the lower part brown and the upper part hyaline, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, intercalary, cylindrical, 14–27 μm long, 3–7 μm wide, with denticles, arising laterally from the lower portion of conidiophores as tiny tooth-like protrusions (2.9–4 μm long, 1.7–2.4 μm wide), hyaline to pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 55–80 μm diam. and conidial filament 6–9 μm wide in the broadest part (\( \bar{x} \) = 65 × 7.5 μm, n = 20), tapering to 3.5–4.5 μm wide near the apex and the base, 525–640 μm long, 46–55-septate, coiled 1½–2½ times, becoming loosely coiled in water, hyaline to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 16 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 14 May 2016, Yong-Zhong Lu, PF01–6 (HKAS 97437, holotype; GZAAS 16–0092, isotype), ex-type living culture, GZCC 16–0080.

Notes: Helicoma multiseptatum is morphologically similar to H. hongkongense in having conidiophores that are branched and/or unbranched, the lower part brown and the upper part hyaline, conidiogenous cells are integrated, intercalary, with denticles arising laterally from the lower portion of conidiophores. But they can be distinguished by conidial features. The conidia of H. multiseptatum are coiled 1½–2½ times and becoming loosely coiled in water, but those of H. hongkongense are coiled 2–2¾ times and does not become loose in water. The conidia of H. multiseptatum are obviously larger than H. hongkongense (55–80 μm diam., 525–640 μm long, up to 55-septa vs. 40–48 μm diam., 205–250 μm long, up to 25-septa). Phylogenetically, H. multiseptatum shares a sister relationship to H. fusiforme and the phylogenetic result supports that they are distinct species (Fig. 15).


Helicoma rubriappendiculatum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554842; Facesoffungi number: FoF 04717; Fig. 21

Fig. 21
figure 21

Helicoma rubriappendiculatum (MFLU 17–1113, holotype). a, b Colony on decaying wood. c Conidiophore with attached conidium. d–g Conidiophores. h, i Conidiogenous cells. j–n Conidia. o, p Colonies on PDA from above and below. Scale bars: a, b = 100 µm, c–g = 50 µm, h–n = 20 µm

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Holotype: MFLU 17–1113

Etymology: “rubriappendiculatum” referring to this fungus having a red appendant in the upper part of conidiophores.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a mountain. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, hyaline to white, with red spot. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, erect, straight to slightly bent, unbranched, septate, 140–220 μm long, 5.5–7 μm wide, the lower part brown and the upper part pale brown, with red appendant near apex, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, intercalary, cylindrical, 11–14 μm long, 5.5–6 μm wide, with denticles, arising laterally from the lower portion of conidiophores as tiny tooth-like protrusions (2.4–3.7 μm long, 1.3–1.6 μm wide), brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 25–35 μm diam. and conidial filament 3–4 μm wide (\( \bar{x} \) = 28 × 3.5 μm, n = 20), 170–270 μm long, 22–29-septate, slightly constricted at septa, coiled 2–3½ times, becoming loosely coiled in water, guttulate, hyaline to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, with flat surface, edge undulate, reaching 26 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on decaying wood in a mountain, 25 January 2017, Yong-Zhong Lu, MRC14 (MFLU 17–1113, holotype; HKAS 100786, isotype), ex-type living cultures, MFLUCC 18–0491, TBRC.

Notes: Morphologically, Helicoma rubriappendiculatum resembles Helicoma aquaticum and Helicoma rufum in having similar conidial morphology. However, this species can be distinguished from H. aquaticum by its longer conidiophores (140–220 μm vs. 70–145 μm long), and from H. rufum by its narrower conidiophores (5.5–7 μm vs. 7–8.5 μm wide), as well as narrower and shorter conidial filaments (3–4 × 170–270 μm vs. 4–5.5 × 240–410 μm). Furthermore, H. rubriappendiculatum differs from all of known helicosporous hyphomycetes in having a red appendant attached near the apex of conidiophores (see Fig. 21a–f). Phylogenetically, H. rubriappendiculatum shares a sister relationship to H. pannosum (Fig. 15) and phylogeny supports that they are distinct species. We compared their DNA sequences and noted that there are 14 noticeable nucleotide differences among the 561 nucleotides in the ITS regions between H. rubriappendiculatum (MFLUCC 18–0491) and H. pannosum (NBRC 9207), which also support them as distinct species.


Helicoma rufum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554843; Facesoffungi number: FoF 04718; Fig. 22

Fig. 22
figure 22

Helicoma rufum (MFLU 17–1115, holotype). a Colony on decaying wood. b, c Conidiogenous cells. d–g Conidiophores. h–l Conidia. m, n Colonies on PDA from above and below. Scale bars: a = 100 µm, b, c, h–j = 20 µm, d–g, k, l = 50 µm

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Holotype: MFLU 17–1115

Etymology: “rufum” referring to this fungus producing reddish brown pigment in PDA medium.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a mountain. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, hyaline to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, erect, straight to slightly bent, mostly unbranched, septate, 110–210 μm long, 7–8.5 μm wide, the lower part brown and the upper part pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, intercalary, cylindrical, 9–14 μm long, 5.5–8.5 μm wide, with denticles, arising laterally from the lower portion of conidiophores as tiny tooth-like protrusions (2.5–3.6 μm long, 1.5–2 μm wide), brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 35–45 μm diam. and conidial filament 4–5.5 μm wide (\( \bar{x} \) = 41 × 4.5 μm, n = 20), 240–410 μm long, 27–37-septate, slightly constricted at septa, coiled 2–3½ times, becoming loosely coiled in water, guttulate, hyaline to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, with flat surface, edge undulate, reaching 9 mm and started producing reddish brown pigment in 1 week at 28 °C, brown to reddish brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on decaying wood in a mountain, 25 January 2017, Yong-Zhong Lu, MRC16 (MFLU 17–1115, holotype; HKAS 100787, isotype), ex-type living cultures, MFLUCC 17–1806, TBRC.

Notes: Morphologically, Helicoma rufum resembles H. aquaticum and H. rubriappendiculatum in having similar conidia. However, H. rufum can be distinguished from H. aquaticum by its wider conidiophores (7–8.5 μm vs. 5–7 μm wide) and slightly larger tooth-like conidiogenous protrusions (2.5–3.6 μm vs. 1.5–2.9 μm), and from H. rubriappendiculatum by its wider conidiophores (7–8.5 μm vs. 5.5–7 μm), as well as wider and longer conidial filaments (4–5.5 × 240–410 μm vs. 3–4 × 170–270 μm). Furthermore, H. rufum produces reddish brown pigment in PDA medium in 7 days but H. aquaticum and H. rubriappendiculatum lack this characteristic. Phylogenetically, H. rufum is nested in between H. aquaticum and H. rubriappendiculatum with high bootstrap support (Fig. 15) and phylogeny supports them as distinct species.


Helicoma septoconstrictum Y.Z. Lu, J.K. Liu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554844; Facesoffungi number: FoF 04719; Fig. 23

Fig. 23
figure 23

Helicoma septoconstrictum (MFLU 17–1141, holotype). a, b Colony on decaying wood. c–f Conidiophores. g–i Conidia. j Germinating conidium. k, l Colonies on PDA from above and below. m Umbonate colony surface on PDA from above. Scale bars: a, b = 200 µm, c–j = 50 µm

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Holotype: MFLU 17–1141

Etymology: “septoconstrictum” referring to the helicoid conidia which are constricted at septate.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium composed of partly immersed, partly superficial, pale brown to brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, straight, mostly unbranched, septate, 120–180 (–241) μm long, 6–9 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, intercalary, cylindrical, 15–16.5 μm long, 5–9 μm wide, with denticles, arising laterally from the lower portion of conidiophores as tiny tooth-like protrusions (3.2–7.2 μm long, 2.7–4 μm wide), pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, enlarged and rounded at tip, 95–140 μm diam. and conidial filament 8–12 μm wide in the broadest part (\( \bar{x} \) = 115 × 10 μm, n = 20), tapering to 4–5 μm wide near the apex and the base, 730–840 μm long, 47–53-septate, constricted at septa, coiled 1½–2 times, becoming loosely coiled in water, pale brown to brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, center umbonate, with rough surface, wrinkle, edge undulate, reaching 35 mm in 3 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW10 (MFLU 17–1141, holotype; HKAS 100812, isotype), ex-type living cultures, MFLUCC 17–2001, TBRC; Ibid., TW03–2 (MFLU 17–1131 = HKAS 100802, paratype), living culture, MFLUCC 17–1991.

Notes: Morphologically, Helicoma septoconstrictum resembles H. longisporum in conidiophores and conidiogenous cells as well as in conidia, and their sizes are also nearly identical (Table 1). We cannot distinguish them based on morphological characteristics but our phylogeny indicates that they segregate in different lineages (Fig. 15). We compare their DNA sequences and noted that there are 25, 8, 82 and 43 noticeable nucleotide differences between the ex-type strain of H. septoconstrictum (MFLUCC 17–2001) and H. longisporum (MFLUCC 17–1997) in ITS, LSU, RPB2 and TEF1α sequence data respectively, which support them as distinct species.

Table 1 Synopsis of atypical Helicoma-like Helicoma asexual morph species
Full size table

Helicoma tectonae Y.Z. Lu, J.K. Liu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554845; Facesoffungi number: FoF 04794

Etymology: Name refers to the host genus Tectona on which the fungus was collected.

Type: THAILAND, Chiang Rai, Chiang Saen District, Wiang Sub district, on decaying inner-surface of bark on Tectona grandis, 9 September 2012, M. Doilom, MFLU 15–3426, ex-type living culture MFLUCC 12–0563, MKT 079.

Known distribution: Thailand.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Doilom et al. (2017, as Helicoma siamense).

Notes: This taxon was introduced as Helicoma siamense in Doilom et al. (2017) who pointed out that this taxon and H. siamense (MFLU 10–0053) were morphologically different in conidial size and shape as well as conidiophores. They anticipated those morphological variations, as one was described from cultures of single ascospore isolations and one from natural decaying woody substrate. Our multi-gene phylogenetic result indicates a close relationship of H. tectonae to H. siamense, but they can be considered as distinct species (Fig. 15).

New combinations of Helicoma

Helicoma elinorae (Linder) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium elinorae Linder, Ann. Mo. bot. Gdn 16: 290 (1929)

Index Fungorum: IF 554846; Facesoffungi number: FoF 04795

Type: SURINAM, Upper Cottica River, on decaying chips of wood, Linder, 382, Type (F, L).

Possible distribution: Colombia, India, Surinam.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Linder (1929, as Helicosporium elinorae).

Notes: This taxon was introduced as Helicosporium elinorae by Linder (1929) because its morphology differs from other Helicosporium species by the granular roughening of the terminal cells of the conidiophores. Matsushima (1975) treated this taxon and other four species (Drepanospora pannosa, Helicosporium linderi, H. nematosporum, H. serpentinum) as Helicosporium pannosum. Goos (1989) synonymized all of them under Drepanospora pannosum. Zhao et al. (2007) treated all of them as well as Helicosporium gigasporum under Helicosporium pannosum. We compared all of descriptions of these seven taxa from their original studies, and found these taxa can be distinguished by the shape or size of conidiophores or conidiogenous cells or conidia. We also compared their morphological features to our new collections introduced in the present study and other known Helicosporous species as well. Their morphologies do not tally with Helicosporium but are similar to our new Helicoma isolates introduced in the present study (see Table 1). Therefore, we reappraise them as Helicoma cocois, H. elinorae, H. gigasporum, H. nematosporum, H. pannosa and H. serpentinum, respectively.

Helicoma elinorae differs from other Helicoma species by the granular roughening of the terminal cells of the conidiophores. The complete description of Helicoma elinorae is described by Linder (1929) as Helicosporium elinorae.


Helicoma gigasporum (C.K.M. Tsui, Goh, K.D. Hyde & Hodgkiss) Y.Z. Lu, comb. nov.

≡ Helicosporium gigasporum C.K.M. Tsui, Goh, K.D. Hyde & Hodgkiss, Mycologia 90(2): 392 (1998)

Index Fungorum: IF 554847; Facesoffungi number: FoF 04796

Type: CHINA, Hong Kong, Tai Po, Lam Tsuen River, on submerged wood, Sep 1997, K. M. Tsui and Ken Wong, KM37 [IFRD 8764, holotype], ex-type living culture, HKUCC 3640.

Possible distribution: Brazil, China (Hong Kong).

Habitat: Aquatic.

Description: For a complete description of this taxon see Tsui et al. (2001, as Helicosporium gigasporum).

Notes: This taxon was introduced as Helicosporium gigasporum in Tsui et al. (2001). We transfer this taxon to Helicoma as its morphology does not align well with Helicoma species and is distinct from Helicosporium. Helicoma gigasporum is similar to H. hongkongense in having conidiophores brown at the lower part and hyaline at the upper part, integrated, intercalary conidiogenous cells, with conidiogenous denticles arising laterally from the lower portion of conidiophores. However, H. gigasporum can be distinguished from H. hongkongense by its loosely helicoid conidia and larger conidia diameter (70–80 μm vs. 40–50 μm). Moreover, Helicoma gigasporum is similar to H. aquaticum in having conidia slightly constricted at septa and the shape of septa resembles each other, but H. gigasporum can be distinguished by its obviously larger conidial diameter (70–80 μm vs. 33–40 μm), wider conidial filaments (6–7 μm vs. 3–5 μm) as well as longer conidiophores (170–250 μm vs. 70–145 μm).


Helicoma hongkongense (K.M. Tsui, Goh, K.D. Hyde) Y.Z. Lu, comb. nov.

≡ Helicosporium hongkongense C.K.M. Tsui, Goh, K.D. Hyde & Hodgkiss, Mycologia 90(2): 392 (1998)

Index Fungorum: IF 554848; Facesoffungi number: FoF 04720; Fig. 24

Fig. 24
figure 24

Helicoma hongkongense (MFLU 17–1145, epitype). a, b Colony on decaying wood. c Conidiophores with attached conidia. d, e Conidiophores. f–h Conidiogenous cells. j–n Conidia. o Germinating conidium. p, q Colonies on PDA from above and below. Scale bars: a, b = 100 µm, c–e = 50 µm, f–h = 10 µm, i–o = 20 µm

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Type: MFLU 17–1145 (Epitype).

Known distribution: China (Hong Kong), Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, light green to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, branched or unbranched, septate, 110–280 μm long, 6–10 μm wide at bottom, tapering to 2.5–3 μm wide at apex, the lower part brown and the upper part hyaline, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, intercalary, cylindrical, 12–22 μm long, 4.5–8 μm wide, with denticles, arising laterally from the lower portion of conidiophores as tooth-like protrusions (2.4–4.6 μm long, 1.7–2.9 μm wide), hyaline to pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 40–48 μm diam. and conidial filament 6–9 μm wide in the broadest part (\( \bar{x} \) = 44 × 7.5 μm, n = 20), tapering to 2–3 μm wide near the apex, 4–6 μm wide at the base, 205–250 μm long, 20–25-septate, slightly constricted in septa, coiled 2–2¾ times, not becoming loose in water, light green to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 9 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Rayong, Klaeng, Thang Kwian, on submerged decaying wood in a freshwater stream, 24 April 2017, Yong-Zhong Lu, RK01 (MFLU 17–1145, epitype designated here; HKAS 100816, isoepitype), ex-epitype living culture, MFLUCC 17–2005.

Notes: Our new isolate morphologically resembles Helicosporium hongkongense (Tsui et al. 2001) in conidiophores, conidiogenous cells and conidial features and even their measurements are also identical. However, its morphological characters are distinct from Helicosporium species, but similar to Helicoma aquaticum, H. multiseptatum and H. septoconstrictum. Furthermore, our phylogeny tree shows that our new isolate (MFLUCC 17–2005) grouped within Helicoma and sister to H. siamense (MFLUCC 10–0120) (Fig. 15). Therefore, we synonymize Helicosporium hongkongense under Helicoma hongkongense. Because the holotype of this species (HKU(M) 12332) was lost during transit from Hong Kong to Kunming (Chen et al. 2010), we designated our new isolate (MFLU 17–1145) as epitype.


Helicoma linderi (R.T. Moore) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium linderi R.T. Moore, Mycologia 46(1): 90 (1954)

Index Fungorum: IF 555345; Facesoffungi number: FoF 04846

Type: Panama Canal Zone, Fort Sherman area, in folio putrido Cocos, 26 August 1952, GWM 8737 (in herb. SUI).

Possible distribution: China, Panama.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Moore (1954, as Helicosporium linderi) and Zhao et al. (2007, Helicosporium pannosum).

Notes: Helicosporium linderi was introduced by Moore (1954). Matsushima (1975) synonymized it under Helicosporium pannosum. Goos (1989) synonymized it under Drepanospora pannosa. Tsui et al. (2006) provided the ITS and LSU sequence data for Helicosporium linderi but their phylogenetic result showed that H. linderi nested among Helicoma species with high bootstrap support. Zhao et al. (2007) treated it as Helicosporium pannosum, and reported a new record which morphology did tally with Helicosporium linderi described in Moore (1954). Boonmee et al. (2014) named Helicosporium linderi as Helicoma linderi in their phylogenetic tree, but did not formally synonymize it.

We synonymize Helicosporium linderi as Helicoma linderi based on its morphological characters being distinct from Helicosporium species but similar to Helicoma species. Helicoma linderi is similar to Helicoma aquaticum, H. rufum and H. rubriappendiculatum in conidial morphology but can be distinguished by the longer conidiophores (see Table 1). Phylogenetically, Helicosporium linderi (NBRC 9207) shares a sister relationship to H. rubriappendiculatum and the phylogenetic analysis supports that they are distinct species (Fig. 15).


Helicoma nematosporum (Linder) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium nematosporum Linder, Ann. Mo. bot. Gdn 16: 288 (1929)

Index Fungorum: IF 554849; Facesoffungi number: FoF 04721; Fig. 25

Fig. 25
figure 25

Helicoma nematosporum (MFLU 17–1159, reference specimen). a Colony on decaying wood. b–e Conidiophores with attached conidia. c–f Conidiophores. f, g Conidiogenous cells. h–k Conidia. l, m Colonies on MEA from above and below. Scale bars: a = 200 µm, b–e, h–k = 50 µm, f, g = 10 µm

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Reference specimen: HKAS 100710

Possible distribution: British Guiana, Japan, Thailand▲, USA (Connecticut, Ohio).

Habitat: Aquatic, Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, branched or unbranched, septate, 150–265 μm long, 5–6 μm wide, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, intercalary, cylindrical, 10–15 μm long, 4–5.5 μm wide, with denticles, arising laterally from conidiophores as tooth-like protrusions (2.7–4.2 μm long, 1.6–1.9 μm wide), pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 35–45 μm diam. and conidial filament 4–5.5 μm wide (\( \bar{x} \) = 39 × 5 μm, n = 20), 310–490 μm long, 30–34-septate, slightly constricted at septa, tightly coiled 2–3 times, becoming loosely coiled or uncoiled in water, guttulate, hyaline to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, circular, with flat surface, edge entire, reaching 26 mm in 2 weeks at 28 °C, brown to dark brown in MEA medium, red pigmented after 2 weeks. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Uttaradit, Laplae, Mae Phun, Ban Ton Klua, on decaying wood in a freshwater stream, 24 October 2015, Saranyaphat Boonmee, UTD10 (MFLU 17–1159, reference specimen designated here; HKAS 100710), living culture, MFLUCC 16–0011.

Notes: Our fresh collection is morphologically similar to Helicosporium nematosporum (Linder 1929) in conidiophores, conidiogenous cells and conidia, even their sizes are also identical. We also compared its morphology to other Helicosporium species and they are obviously distinct with respect to conidiophores and conidia. Furthermore, phylogenetically our fresh collection clusters within Helicoma with high bootstrap support (Fig. 15), therefore, we synonymize Helicosporium nematosporum as Helicoma nematosporum. Since the type material of Helicoma nematosporum deposited at FH is available (Linder 1929; Goos 1989) but lacks molecular data, we designate our new isolate MFLU 17–1159 as reference specimen.


Helicoma pannosum (Berk. & M.A. Curtis) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Drepanospora pannosa Berk. & M.A. Curtis, in Berkeley, Grevillea 3(no. 27): 105 (1875)

≡ Helicosporium pannosum (Berk. & M.A. Curtis) R.T. Moore, Mycologia 49: 582 (1957)

Index Fungorum: IF 554850; Facesoffungi number: FoF 04797

Type: Forming a cloth-like stratum on the cut surface of stumps. Inf. No. 2354

Possible distribution: North American.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Moore (1957, as Helicosporium pannosum).

Notes: Drepanospora pannosa and Helicosporium pannosum have been transferred several times and are still confused (Moore 1957; Matsushima 1975; Goos 1989; Zhao et al. 2007). Drepanospora pannosa was introduced by Berkeley (1875). Moore (1957) synonymized it as Helicosporium pannosum. Matsushima (1975) synonymized Drepanospora pannosa, Helicosporium elinorae, H. linderi, H. nematosporum and H. serpentinum under Helicosporium pannosum. Goos (1989) synonymized Helicosporium elinorae, H. linderi, H. nematosporum, H. pannosum and H. serpentinum under Drepanospora pannosa. Zhao et al. (2007) treated all these taxa and Helicosporium gigasporum as H. pannosum.

We compared all descriptions of these seven taxa from their original studies (Linder 1929; Moore 1954, 1957; Matsushima 1975; Goos 1989; Zhao et al. 2007), and found that even they are morphologically similar, they can be distinguished by the shape or size of conidiophores or conidiogenous cells or conidia. We also compared their morphology to our new collections introduced in the present study and other known Helicosporium species. Their morphs do not align with those of Helicosporium, but are similar to Helicoma. Therefore, we reappraise them in this study (also see the notes of Helicoma elinorae).

We synonymize Drepanospora pannosa and Helicosporium pannosum as Helicoma pannosum. Helicoma pannosum is similar to H. brunneisporum in conidiophore characters, but can be distinguished by the thinner conidia (7–8 μm vs. 9–14 μm) (see Table 1).


Helicoma serpentinum (Linder) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium serpentinum Linder, Ann. Mo. bot. Gdn 16: 288 (1929)

Index Fungorum: IF 554851; Facesoffungi number: FoF 04798

Possible distribution: New Guinea, USA (Missouri).

Type: USA, Missouri, Pacific, on decaying wood, Oct. 1927, Linder, TYPE (F, L, MBG 64721)

Description: For a complete description of this taxon see Linder (1929, Helicosporium serpentinum).

Habitat: Terrestrial.

Notes: Helicosporium serpentinum was introduced by Linder (1929) based on its morphology which is similar to Helicosporium nematosporum, but differs in dimensions of the conidia and conidiophores as well as the stouter and branched sporogenous teeth. Matsushima (1971) reported a new record of H. serpentinum. Matsushima (1975) synonymized it under Helicosporium pannosum. Goos (1989) synonymized it under Drepanospora pannosa. Zhao et al. (2007) treated it as Helicosporium pannosum. In this study, we note that Helicosporium serpentinum is morphologically similar to Helicoma elinorae, H. longisporum and H. septoconstrictum but distinct to Helicosporium species. Therefore, we synonymize Helicosporium serpentinum as Helicoma serpentinum. Helicoma serpentinum differs from other Helicoma species by its conidia that are acropleurogenous from the sporogenous teeth in the whole conidiophores.

Other accepted Helicoma species

Helicoma acrophalerium R.T. Moore, Mycologia 49: 584 (1957)

Index Fungorum: IF 298224

Known distribution: Puerto Rico.

Habitat: Terrestrial.

Notes: Moore (1957) pointed out that the type material of Helicoma acrophalerium was deposited at NY but Goos (1986) mentioned the specimen was unavailable.


Helicoma anastomosans Linder, Ann. Mo. bot. Gdn 18: 13 (1931)

Index Fungorum: IF 246269

Possible distribution: British Guiana, China (Hainan).

Habitat: Terrestrial.

Notes: Helicoma anastomosans is morphologically similar to H. repens (Morgan 1892) and H. tenuifilum (Linder 1931) in conidial shape, but can be distinguished by its conidiophore features. Zhao et al. (2007) introduced a new record of H. anastomosans from China and provided more detailed morphological information.


Helicoma asperothecum Linder, Ann. Mo. bot. Gdn 16: 311 (1929)

Index Fungorum: IF 257514

Known distribution: Chile.

Habitat: Terrestrial.

Notes: Linder (1929) pointed out that Helicoma asperothecum resembles H. ambiens and H. curtisii, but differs from them in the roughened walls of the conidiophores. Goos (1986) accepted Linder’s identification.


Helicoma atroseptatum Linder, Ann. Mo. bot. Gdn 16: 307 (1929)

Index Fungorum: IF 257779

Possible distribution: Chile, New Zealand, USA (Hawaii).

Habitat: Terrestrial.

Notes: Linder (1929) pointed out that Helicoma atroseptatum grew in association with H. asperothecum, and it is readily distinguished by the simple, erect conidiophores and its distinct conidia characters. Goos (1980) introduced a new record of H. atroseptatum from Hawaii. Goos (1986) re-described this taxon.


Helicoma casuarinae (Matsush.) G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 434 (2007)

≡ Helicomyces casuarinae Matsush., Matsush. Mycol. Mem. 4: 9 (1985)

Index Fungorum: IF 510640

Known distribution: China (Taiwan).

Habitat: Terrestrial.

Notes: Matsushima (1985) described Helicomyces casuarinae with distinguishable non-hygroscopic coiled conidia. Zhao et al. (2007) transferred it into Helicoma based on its erect and denticulate conidiophores.


Helicoma dennisii M.B. Ellis, Mycol. Pap. 87: 23 (1963)

Index Fungorum: IF 331766

Possible distribution: Argentina, Brazil, Britain, China (Hainan, Taiwan, Yunnan), Cuba, India, Japan, Malaysia, New Guinea, South Africa, USA (Alabama, Hawaii), Venezuela.

Habitat: Terrestrial.

Notes: Ellis (1963, 1976), Matsushima (1971, 1975), Morgan-Jones (1974), Goos (1980), Goos (1986), Zhao et al. (2007) and de Castro et al. (2012) have described Helicoma dennisii. Tsui et al. (2006) provided its ITS and LSU sequence data (NBRC 30667). Our phylogenetic result showed that H. dennisii shares a sister relationship to H. inthanonense and H. guttulatum with good bootstrap support (Fig. 15).


Helicoma divaricata Hol.-Jech., Česká Mykol. 41(1): 33 (1987)

Index Fungorum: IF 130211

Known distribution: Cuba.

Habitat: Terrestrial.

Notes: Helicoma divaricata was introduced by Holubová-Jechová (1987). This taxon was only known from its holotype. New collections and molecular data are needed to solve the phylogenetic status of Helicoma divaricata.


Helicoma eucalypti P.N. Singh & S.K. Singh, Current Research in Environmental & Applied Mycology 6(4): 249 (2016)

Index Fungorum: IF 817603

Known distribution: India (Maharashtra).

Habitat: Terrestrial.

Notes: Helicoma eucalypti was introduced by Singh and Singh (2016). This taxon is similar to H. narsapurensis in having typical Helicoma conidial features but differs in conidiophores characters.


Helicoma guttulatum Y.Z. Lu, Boonmee & K.D. Hyde, Fungal Diversity 80: 125 (2016)

Index Fungorum: IF 552218

Known distribution: Thailand.

Habitat: Aquatic.

Notes: Helicoma guttulatum was introduced by Hyde et al. (2016a) based on morphology and phylogenetic evidence. This taxon shares similar morphological features to the type species of Helicoma, but can be distinguished by its longer and narrower conidiophores and larger conidial size.


Helicoma hainanense G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 399 (2007)

Index Fungorum: IF 510636

Known distribution: China (Hainan).

Habitat: Terrestrial.

Notes: Helicoma hainanense is morphologically similar to H. stigmateum in having 1¼–1¾ times coiled and hyaline to subhyaline conidia, but differs by its macronematous bent-ascending conidiophores and larger conidia (Zhao et al. 2007).


Helicoma hyalonema G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 401 (2007)

Index Fungorum: IF 510637

Known distribution: China (Hainan).

Habitat: Terrestrial.

Notes: Helicoma hyalonema morphologically resembles H. anastomosans, H. limpidum, H. morganii, H. polysporum, H. repens and H. tenuifilum in conidial features but can be distinguished by conidiophore characters (Zhao et al. 2007).


Helicoma indicum Gawas & Bhat, Mycotaxon 100: 298 (2007)

Index Fungorum: IF 510703

Known distribution: India.

Habitat: Terrestrial.

Notes: Helicoma indicum is morphologically distinct to other known Helicoma species by its uniseptate conidia and overall dimensions (Gawas and Bhat 2007). This fungus was only known from its holotype.


Helicoma inflatum Linder, Mycologia 25(5): 344 (1933)

Index Fungorum: IF 267881

Known distribution: USA (Missouri).

Habitat: Terrestrial.

Notes: Helicoma inflatum was introduced by Linder (1933). Goos (1986) reexamined the type material and provided detailed morphological descriptions with figures.


Helicoma intermedium (Penz. & Sacc.) Linder, Ann. Mo. bot. Gdn 16: 306 (1929)

≡ Helicosporium intermedium Penz. & Sacc., Malpighia 15: 249 (1902)

Index Fungorum: IF 268046

Possible distribution: Colombia, Indonesia (Bogor).

Habitat: Terrestrial.

Notes: This taxon was introduced by Penzig and Saccardo (1902). Linder (1929) transferred it to Helicoma based on its distinctive size and shape of the conidia. Goos (1986) reexamined its type specimen and suggested that this taxon should be retained in Helicosporium. We compared its morphological features described by Linder (1929) and Goos (1986) to other known helicosporous species and its morphological features tally well with Helicoma but distinct from Helicosporium. Therefore, we accept Linder’s treatment and retained it as a Helicoma species.


Helicoma inthanonense (Boonmee & K.D. Hyde) Boonmee & K.D. Hyde, Fungal Diversity 68 (1): 265 (2014)

≡ Thaxteriella inthanonensis Boonmee & K.D. Hyde, Fungal Diversity 51(1): 86 (2011)

Index Fungorum: IF 804555

Known distribution: Thailand.

Habitat: Terrestrial.

Notes: This taxon was introduced as Thaxteriella inthanonensis in Boonmee et al. (2011). Boonmee et al. (2014) synonymized it as Helicoma inthanonense based on phylogenetic evidence. The asexual morph of H. inthanonense was found from the cultures which was isolated from its sexual morph specimens and characterized by helicoid conidia with secondary microconidia (Boonmee et al. 2011).


Helicoma jianfenglingense J.M. Gao & X.G. Zhang, Mycotaxon 131(2): 352 (2016)

Index Fungorum: IF 817482

Known distribution: China (Hainan).

Habitat: Terrestrial.

Notes: Helicoma jianfenglingense differs from other Helicoma species by its semi-helicoid conidia (Gao et al. 2016). This fungus was only known from its holotype.


Helicoma khunkornense (Boonmee & K.D. Hyde) Boonmee & K.D. Hyde, Fungal Diversity 68: 265 (2014)

≡ Tubeufia khunkornensis Boonmee & K.D. Hyde, Fungal Diversity 51(1): 69 (2011)

Index Fungorum: IF 804554

Known distribution: Thailand.

Habitat: Terrestrial.

Notes: This taxon was introduced as Tubeufia khunkornensis in Boonmee et al. (2011). Boonmee et al. (2014) synonymized it as Helicoma khunkornense based on phylogenetic evidence. The asexual morph of H. khunkornense was found from the cultures which was isolated from its sexual morph specimens and characterized by helicoid conidia (Boonmee et al. 2011).


Helicoma latifilum G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 403 (2007)

Index Fungorum: IF 510630

Known distribution: China (Ningxia).

Habitat: Terrestrial.

Notes: Helicoma latifilum differs from other Helicoma species by its swollen subhyaline conidiogenous cells and broader conidial filaments (Zhao et al. 2007). This taxon might not belong to Helicoma because its conidiophore morphology differs from other Helicoma species. We, however, retain this species due to a lack of strong morphological evidence for any transfer.


Helicoma limpidum Morgan, J. Cincinnati Soc. Nat. Hist. 15: 47 (1892)

≡ Helicosporium limpidum (Morgan) Sacc., Syll. fung. (Abellini) 11: 639 (1895)

Index Fungorum: IF 145369

Known distribution: USA (Ohio).

Habitat: Terrestrial.

Notes: Both Linder (1929) and Goos (1986) accepted this species as Helicoma species and provided its descriptions and figures.


Helicoma microscopicum (Ellis) Linder, Ann. Mo. bot. Gdn 16: 299 (1929)

≡ Helicosporium microscopicum Ellis, Bull. Torrey bot. Club 9(6): 98 (1882)

≡ Helicomyces microscopicus (Ellis) Pound & Clem., Minn. bot. Stud. 1(Bulletin 9): 659 (1896)

Index Fungorum: IF 271078

Known distribution: USA (New Jersey).

Habitat: Terrestrial.

Notes: Linder (1929) synonymized this taxon under Helicoma microscopicum and provided a complete description and morphological figures. Goos (1986) accepted Linder’s treatment. Zhao et al. (2007) introduced a new record from China. However, we compared its morphological features and descriptions to those provided by Linder (1929) and Goos (1986). They are distinct in conidiophores and conidiogenous cells, as well as the conidia. Both Linder (1929) and Goos (1986) described the conidiophores of H. microscopicum as hyaline, erect or bent, up to 30 μm long and 2.7–3 μm wide; conidiogenous cells mono- or polyblastic, integrated, denticulate; conidial filaments tightly coiled 2–2¾ times, 12–20-septate, 11–12.5 μm diam. But Zhao et al. (2007) described their isolate as conidiophores micronematous or lacking; conidiogenous cells monoblastic, acrogenous or incorporated with creeping hyphae; conidia filament tightly coiled 1¼–1¾ times, 6–9-septate, conspicuously constricted at septa, 9–12 μm diam. Therefore, we considered that these two isolates should be distinct species, but we do not name the isolate of Zhao et al. (2007, as Helicoma microscopicum) as its conidiophores’ features do not fit into the generic concept of Helicoma.


Helicoma minutissimum Linder, Ann. Mo. bot. Gdn 16: 298 (1929)

Index Fungorum: IF 271332

Known distribution: USA (Massachusetts).

Habitat: Terrestrial.

Notes: Helicoma minutissimum is different from other Helicoma species by its smaller conidia size (Linder 1929). Goos (1986) mentioned that he failed to find the taxon from the type material but had studied the slides prepared by Linder (1929).


Helicoma miscanthi (W.H. Hsieh, Chi Y. Chen & Sivan.) Boonmee & K.D. Hyde, Fungal Diversity 68: 267 (2014)

≡ Tubeufia miscanthi W.H. Hsieh, Chi Y. Chen & Sivan., Mycol. Res. 102(2): 234 (1998)

≡ Taphrophila miscanthi (W.H. Hsieh, Chi Y. Chen & Sivan.) Réblová & M.E. Barr, Sydowia 52(2): 283 (2000)

Index Fungorum: IF 550637

Known distribution: China (Taiwan), Thailand.

Habitat: Terrestrial.

Notes: This taxon was introduced as Tubeufia miscanthi by Hsieh et al. (1998). Réblová and Barr (2000) transferred it to Taphrophila miscanthi. Boonmee et al. (2014) reported a new record of this species and transferred T. miscanthi to Helicoma based on their phylogenetic evidence.


Helicoma muelleri Corda, Icon. fung. (Prague) 1: 15 (1837)

≡ Helicosporium muelleri (Corda) Sacc., Michelia 2(no. 6): 129 (1880)

≡ Helicomyces muelleri (Corda) Pound & Clem., Minn. bot. Stud. 1(Bulletin 9): 659 (1896)

= Helicomyces curtisii (Berk.) Pound & Clem., Minn. bot. Stud. 1(Bulletin 9): 658 (1896)

= Helicoma curtisii Berk., Grevillea 3(no. 27): 106 (1875)

= Helicosporium tiliae Peck, Bull. Torrey bot. Club 34: 103 (1907)

Index Fungorum: IF 238937

Possible distribution: Belgium, Canada (Gatineau, Ontario), England, France, Germany, Mexico, Morocco, New Zealand, Norway, Slovakia, Sri Lanka, Sweden, Tanzania, USA (Connecticut, Hawaii, Maine, Massachusetts, New Jersey, New York).

Habitat: Terrestrial.

Notes: Helicoma muelleri is the type species of Helicoma. Linder (1929), Talbot (1951), Moore (1953), Ellis (1971), Pirozynski (1972), Goos (1980, 1986) and Boonmee et al. (2014) have described this species. Tsui et al. (2006) provided its ITS and LSU sequence data. Our phylogenetic result shows that Thaxteriella helicoma (UBC F13877) (provided by Tsui et al. 2006) clustered together with Helicoma muelleri (CBS 964.69) with good bootstrap support (Fig. 15) and indicate that they are the same species. We also compared their sequence data and there is no difference in ITS (only ITS is available for UBC F13877) between these two isolates. Therefore, we considered that the isolate UBC F13877 is a potential misidentification, and consider it as Helicoma muelleri.


Helicoma narsapurensis P. Rag. Rao & D. Rao [as ‘narsapurense’], Mycopath. Mycol. appl. 22: 49 (1964)

Index Fungorum: IF 331767

Known distribution: India.

Habitat: Terrestrial.

Notes: Helicoma narsapurensis was only known from its holotype. Goos (1986) described this species based on the description of Rao and Rao (1964).


Helicoma palmarum G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 434 (2007)

≡ Tubeufia palmarum (Torrend) Samuels, Rossman & E. Müll., Sydowia 31(1–6): 189 (1979) [1978]

≡ Ophionectria palmarum Torrend, Bull. Jard. bot. État Brux. 4: 8 (1914)

Index Fungorum: IF 510650

Possible distribution: Brazil, Colombia, Congo, Peru, Venezuela.

Habitat: Terrestrial.

Notes: Samuels et al. (1979) reported that the asexual morph of Tubeufia palmarum was produced from its sexual morph’s cultures which also formed helicoid conidia. Zhao et al. (2007) transferred the asexual morph of T. palmarum to Helicoma and named it as Helicoma palmarum. According to Samuels et al. (1979), the asexual and sexual morph of T. palmarum are in line with Helicoma species, therefore, we accept Zhao et al. (2007) and treat both sexual and asexual morphs of Tubeufia palmarum as Helicoma palmarum based on the rule of one fungus one name.


Helicoma phaeosporum Fresen., Beitr. Mykol. 3: 99 (1863)

≡ Helicosporium phaeosporum (Fresen.) Sacc., Syll. fung. (Abellini) 4: 561 (1886)

= Helicosporium boydii A.L. Sm. & Ramsb., Trans. Br. mycol. Soc. 5(1): 67 (1915) [1914]

= Helicosporium spectabile Fautrey & Lambotte, Revue mycol., Toulouse 17(no. 66): 70 (1895)

= Helicoma velutinum Ellis, Bull. Torrey bot. Club 9(11): 134 (1882)

≡ Helicosporium velutinum (Ellis) Sacc., Syll. fung. (Abellini) 4: 561 (1886)

Index Fungorum: IF 239036

Possible distribution: Austria, England, Morocco, USA.

Habitat: Terrestrial.

Notes: Linder (1929) treated Helicosporium boydii, H. phaeosporum and H. spectabile as Helicoma phaeosporum based on their identical morphological features. Goos (1986) reexamined the type specimen of Helicoma velutinum and synonymized it under Helicoma phaeosporum.


Helicoma polysporum Morgan, J. Cincinnati Soc. Nat. Hist. 15: 46 (1892)

≡ Helicosporium polysporum (Morgan) Sacc., Syll. fung. (Abellini) 11: 639 (1895)

Index Fungorum: IF 239184

Possible distribution: Panama, USA (Ohio).

Habitat: Terrestrial.

Notes: Linder (1929) treated Helicosporium polysporum as Helicoma polysporum. Goos (1989) accepted Linder’s evaluation. We accept Linder (1929) and Goos (1989) as its conidial morphological features are similar to Helicoma species.


Helicoma recurvum (Petch) Linder, Ann. Mo. bot. Gdn 16: 312 (1929)

≡ Helicosporium recurvum Petch, Ann. R. bot. Gdns Peradeniya 10(1): 138 (1926)

Index Fungorum: IF 276199

Known distribution: Sri Lanka.

Habitat: Terrestrial.

Notes: This taxon was introduced as Helicosporium recurvum by Petch (1926). Linder (1929) reexamined the type specimen of H. recurvum and transferred it to Helicoma. Goos (1986) reexamined the slide of type specimen and accepted Linder’s treatment.


Helicoma repens Morgan, J. Cincinnati Soc. Nat. Hist. 15: 47 (1892)

≡ Helicosporium repens (Morgan) Sacc., Syll. fung. (Abellini) 11: 639 (1895)

Index Fungorum: IF 239610

Possible distribution: Canada (Toronto), China (Hainan), USA (Ohio, Iowa).

Habitat: Terrestrial.

Notes: Helicoma repens was introduced by Morgan (1892). Linder (1929), Moore (1953) and Goos (1986) have studied this species. Zhao et al. (2007) reported a new record of H. repens from China.


Helicoma roseolum Thaxt., Ann. Mo. bot. Gdn 16: 297 (1929)

Index Fungorum: IF 276784

Known distribution: Grenada.

Habitat: Terrestrial.

Notes: Helicoma roseolum was collected by Roland Thaxter but described by Linder (1929). Goos (1986) reexamined the type specimen and accepted Linder’s identification.


Helicoma rugosum (C. Booth) Boonmee & K.D. Hyde [as ‘rugosa’], Fungal Diversity 68: 266 (2014)

≡ Tubeufia rugosa C. Booth, Mycol. Pap. 94: 13 (1964)

= Thaxteriella helicoma (W. Phillips & Plowr.) J.L. Crane, Shearer & M.E. Barr, Can. J. Bot. 76(4): 610 (1998)

= Tubeufia helicoma (W. Phillips & Plowr.) Piroz., Mycol. Pap. 129: 30 (1972)

≡ Sphaeria helicoma W. Phillips & Plowr., Grevillea, 6: 26 (1877)

Index Fungorum: IF 821048

Known distribution: Bermuda.

Habitat: Terrestrial.

Notes: Boonmee et al. (2014) synonymized Tubeufia rugosa, Thaxteriella helicoma and Sphaeria helicoma under Helicoma rugosum based on phylogenetic and morphological evidence. Our phylogenetic analysis (Fig. 15) shows that there are three Tubeufia paludosa isolates that cluster together with Helicoma rugosum JCM 2739, viz. ANM 196, ANM 953 and ANM 1169 (Promputtha and Miller 2010), and the topology shows that they should be the same species. Therefore, we renamed these three isolates as Helicoma rugosum. Besides, the isolate T. paludosa (HKUCC 9118) (Kodsueb et al. 2006) shares a sister relationship to H. rugosum and phylogeny shows that they are probably distinct species, thus, we renamed it to Helicoma sp. (HKUCC 9118) as the original authors only provided its sequence data but did not describe its morphology.


Helicoma scarabaeiforme G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 422 (2007)

Index Fungorum: IF 510631

Known distribution: China (Hainan).

Habitat: Terrestrial.

Notes: Helicoma scarabaeiforme is characterized by the denticulate conidiophores and non-hygroscopic conidia usually coiled in one plane (Zhao et al. 2007).


Helicoma siamense Boonmee & K.D. Hyde, Fungal Diversity 68: 268 (2014)

Index Fungorum: IF 804557

Known distribution: Thailand.

Habitat: Terrestrial.

Notes: Boonmee et al. (2014) introduced Helicoma siamense based on phylogenetic evidence. The asexual morph of H. siamense was found from the cultures which was isolated from its sexual morph specimen and characterized by helicoid conidia.


Helicoma stigmateum (Riess) Linder, Ann. Mo. bot. Gdn 16: 298 (1929)

≡ Lituaria stigmatea Riess, Bot. Ztg. 11: 136 (1853)

= Helicomyces niveus Bres. & Jaap, Verh. bot. Ver. Prov. Brandenb. 56: 91 (1914)

= Helicomyces sphaeropsidis A. Potebnia. Bribnie symbionti II. Spaeropsidis i Helicomyces, [21-]28.

Index Fungorum: IF 278881

Possible distribution: Britain, Germany.

Habitat: Terrestrial.

Notes: Linder (1929) synonymized Helicomyces niveus, H. sphaeropsidis and Lituaria stigmatea as Helicoma stigmateum. Goos (1986) accepted Linder’s treatment.


Helicoma taenia R.T. Moore, Mycologia 47(1): 91 (1955)

Index Fungorum: IF 298229

Known distribution: USA (Iowa).

Habitat: Terrestrial.

Notes: Helicoma taenia was described by Moore (1955). Goos (1986) reexamined the type specimen and accepted Moore’s identification.


Helicoma taiwanensis Matsush., Matsush. Mycol. Mem. 3: 11 (1983)

Index Fungorum: IF 108043

Known distribution: China (Taiwan).

Habitat: Terrestrial.

Notes: Helicoma taiwanensis is characterized by Helicoma-like helicoid conidia (Matsushima 1983). Interestingly, Matsushima (1983) found that its cultures produced a kind of phragmosporous conidia.


Helicoma tenuifilum Linder, Ann. Mo. bot. Gdn 18: 14 (1931)

Index Fungorum: IF 249557

Known distribution: USA (Missouri).

Habitat: Terrestrial.

Notes: Linder (1931), Moore (1953) and Goos (1986) have studied this species. Goos (1986) mentioned that secondary conidia are sometimes observed in this species.


Helicoma vaccinii Carris, Mycotaxon 36(1): 29 (1989)

Index Fungorum: IF 126385

Possible distribution: China (Jilin), Peru, USA (Georgia).

Habitat: Terrestrial.

Notes: Helicoma vaccinii was introduced by Carris (1989). Matsushima (1993) described a new record of H. vaccinii from Peru. Zhao et al. (2007) reported a new record from China. Tsui et al. (2006) provided ITS and LSU sequence data for a strain named “Helicoma vaccinii CBS 216.90”, but with no morphological description. Their phylogenetic result showed that H. vaccinii (CBS 216.90) grouped with Helicosporium vegetum. Boonmee et al. (2014) also found that H. vaccinii (CBS 216.90) clusters with Helicosporium vegetum and they renamed this species as Helicosporium vaccinii based on phylogeny, but did not formally synonymize it. Subsequently, Brahamanage et al. (2017), Chaiwan et al. (2017) and Lu et al. (2017a) followed Boonmee’s treatment and named this species as Helicosporium vaccinii. In the present study, our phylogenetic result shows that this strain shares a close relationship to Helicosporium species. However, we compared its morphogy as described by Carris (1989), Matsushima (1993) and Zhao et al. (2007), to other helicosporous species and found that its morphology is similar to Helicoma and differs from Helicosporium. We, therefore, retained it as Helicoma species until new evidence are available.


Helicoma viridis (Corda) S. Hughes, Can. J. Bot. 36: 772 (1958)

≡ Helicocoryne viridis Corda [as ‘viride’], Icon. fung. (Prague) 6: 9, 1854.

= Helicosporium viride (Corda) Sacc., Syll. fung. 4: 558, 1886.

= Drepanospora viridis (Corda) Goos [as ‘viride’], Mycologia 81: 371, 1989.

= Helicosporium brunneolum Berk. & Curt., Grevillea 3: 51, 1874.

≡ Helicomyces brunneolus (Berk. & Curt.) Pound & Clements, Bull. Minn. Geol. Nat. Hist. Survey 9: 658, 1896.

= Helicoma proliferens Linder, Ann. Missouri Bot. Gard. 16: 309, 1929.

Index Fungorum: IF 298230

Possible distribution: Worldwide.

Habitat: Terrestrial.

Notes: Linder (1929) described this species as Helicoma proliferens; Pirozynski (1972) described as Helicosporium viride; Goos (1975) as Helicoma Proliferens; Goos (1986) as Helicosporium viride; Goos (1989) as Drepanospora viride. Zhao et al. (2007) as Helicoma viridis. We accepted Zhao et al. (2007) because of the priority of Helicocoryne viridis over Helicoma proliferens and this taxon is morphologically similar to Helicoma.

Excluded Helicoma species

Helicoma resinae (Lindau) J.L. Crane & Schokn., Mycologia 67(3): 669 (1975)

≡ Torula resinae Lindau, Rabenh. Krypt.-Fl., Edn 2 (Leipzig) 1.8: 578 (1906) [1907]

Index Fungorum: IF 315038

Notes: Goos (1986) reexamined the type specimen of Helicoma resinae and mentioned this species was questionable because it was not typical of Helicoma. But he retained this taxon in Helicoma pending further evidence. We accept Goos (1986) but exclude this taxon from Helicoma as its morphology does not fit into the generic concept of Helicoma at all. New collections and molecular data are needed to resolve its taxonomic problems.


Helicomyces Link, Mag. Gesell. naturf. Freunde, Berlin 3(1–2): 21 (1809)

Index Fungorum: IF 8476

Saprobic on woody substrata. Mycelium partly immersed, septate, branched hyphae. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Conidiophores macronematous, mononematous, cylindrical, unbranched or branched, 0–3-septate, arising as lateral branches from creeping hyphae, subhyaline to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, truncate at apex after conidial secession, hyaline to brown, smooth-walled. Conidia solitary, acrogenous or acropleurogenous, helicoid, rounded at tip, multi-septate, hyaline to pale brown, smooth-walled.

Type species: Helicomyces roseus Link, Mag. Gesell. naturf. Freunde, Berlin. 3: 21 (1809)

Notes: Helicomyces was established by Link (1809), and it is the oldest described helicosporous hyphomycetes genus. Linder (1929) redefined this genus, and many of the species originally assigned to Helicomyces were reassigned to Helicosporium or Helicoma. Moore (1955) provided a key for all of known Helicomyces species. Goos (1985) reviewed the taxonomic status of Helicomyces and provided updated descriptions and a key to accepted species. Zhao et al. (2007) reported a new species and nine new records of Helicomyces from China.

The phylogenetic relationships of Helicomyces are still confused. Phylogenetic relationships of Helicomyces were reported by Tsui and Berbee (2006) and Tsui et al. (2006, 2007). They reported that Helicomyces species were polyphyletic. Boonmee et al. (2014) considered that the clade of Helicomyces roseus (CBS 283.51) represented the genus Helicomyces, and renamed Helicosporium indicum (CBS 374.93) and Helicosporium talbotii (MUCL 33010) as Helicomyces, but did not formally synonymize them. They also found that two isolates of H. roseus (BCC 3381 and BCC 8808) clustered within Tubeufia in a distinct clade and renamed them as Tubeufia roseus but did not formally synonymize them either. Luo et al. (2017) reported five new isolates of H. roseus based on phylogenetic and morphological evidence. Our multi-gene phylogenetic result depicts that the isolates of CBS 283.51 and five isolates from Luo et al. (2017) cluster with other five isolates and represent Clade 2 (Fig. 2). However, except the isolates of Luo et al. (2017), other isolates do not tally with Helicomyces in either conidiophore or conidial morphology. Instead, those isolates in Clade 4 correspond well to Helicomyces in both conidiophores and conidial morphology. Furthermore, the isolate CBS 283.51 differs from previous description of H. roseus in conidiophore and conidial morphology (Linder 1929; Goos 1985; Tsui et al. 2006). Therefore, we consider that the isolate H. roseus (CBS 283.51) was a misidentification and Clade 2 does not represent the genus Helicomyces. Instead, we treat Clade 4 as Helicomyces sensu stricto.

Boonmee et al. (2014) documented the sexual morph of Helicomyces based on the morphology of Helicomyces paludosus, however, we synonymize H. paludosus under Pseudohelicomyces paludosus in this study. The sexual morph of Helicomyces is yet to be determined.

In this study, we introduce a new Helicomyces species, H. hyalosporus, and a new record of H. colligatus and H. torquatus, and synonymize Helicoma chiayiense under Helicomyces chiayiensis, based on phylogenetic and morphological evidence. We also review this genus based on previous descriptions and accept twelve species in Helicomyces including one new species and one new combination, and exclude four species from this genus (shown in Table 3).


Helicomyces colligatus R.T. Moore, Mycologia 46(1): 89 (1954)

Index Fungorum: IF 298234; Facesoffungi number: FoF 04722; Fig. 26

Fig. 26
figure 26

Helicomyces colligatus (MFLU 17–1169, reference specimen). a Colony on decaying wood. b–f Conidiogenous cells. g–l Conidia (notes g, h conidia bear secondary conidia). m, n Colonies on PDA from above and below. Scale bars: a = 200 µm, b–f = 20 µm, g–l = 50 µm

Full size image

Reference specimen: MFLU 17–1169

Possible distribution: China (Yunnan, Hainan), India, Thailand▲, USA (Iowa, Missouri).

Habitat: Aquatic, Terrestrial.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium mostly immersed, partly superficial, composed of branched, septate hyphae, hyaline at first, becoming subhyaline to pale brown, with masses of crowded, cottony conidia. Conidiophores macronematous, mononematous, erect, cylindrical, branched or unbranched, 0–3-septate, arising as lateral branches from creeping hyphae, 20–30 μm long, 3.5–4.5 μm wide, hyaline, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, 10–18 μm long, 3.5–4.5 μm wide, hyaline, smooth-walled. Conidia acrogenous, helicoid, dry, solitary, attached eccentrically and seceding schizolytically, rounded at tip, end cells broadly spathulate, the basal cell bearing a flattened attachment scar, 50–70 μm in diam. and conidial filament 7–11 μm wide in the broadest part (\( \bar{x} \) = 62 × 8.5 μm, n = 20), tapering to 3.5–4 μm wide near apex and base, 270–410 μm long, 38–41-septate, slightly constricted at septa, coiled 1½–2¾ times, becoming loosely coiled in water, guttulate, hyaline, smooth-walled. Some conidia formed small globose to subglobose secondary conidia (Fig. 26g, h), 4.5–6 μm in diam., attached to the margin of the filaments, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 13 mm in 2 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, Saprobic on submerged decaying wood in a freshwater stream, 28 November 2015, Saranyaphat Boonmee and Yong-Zhong Lu, TUB03–2 (MFLU 17–1169, reference specimen designated here; HKAS 100825), living cultures, MFLUCC 16–1132, TBRC.

Notes: Morphologically, the fresh collection resembles Helicomyces colligatus in conidiophores, conidiogenous cells and conidia, including in terms of size (Moore 1954; Rao and Rao 1964; Goos 1985; Zhao et al. 2007). Therefore, we identify our fresh collection as H. colligatus. Phylogenetically, H. colligatus constitutes a strongly supported independent lineage basal to H. chiayiensis, H. hyalosporus and H. torquatus (Fig. 2). Since the type specimen deposited in NYBG (GWM1357) is available but lack molecular data, we designate our newly collected specimen (MFLU 17–1169) as a reference specimen, and this is the first record of the species in Thailand.


Helicomyces hyalosporus Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554852; Facesoffungi number: FoF 04723; Fig. 27

Fig. 27
figure 27

Helicomyces hyalosporus (GZAAS 16–0083, holotype). a Colony on decaying wood. b, c Conidiophores with attached conidia. d, e Conidiophores with a part of attached conidia. f, g Conidiophores and conidiogenous cells. h–l Conidia. m, n Colony on PDA from above and below. Scale bars: b, c, h–l = 50 µm, d–g = 20 µm

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Holotype: GZAAS 16–0083

Etymology: “hyalosporus” referring to hyaline helicoid conidia.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, erect, cylindrical, branched or unbranched, 0–3-septate, arising as lateral branches from creeping hyphae, 20–65 μm long, 4–6 μm wide, hyaline, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 15–25 μm long, 4–5.5 μm wide, hyaline, smooth-walled. Conidia solitary, acrogenous, helicoid, dry, attached eccentrically and seceding schizolytically, rounded at tip, end cells broadly spathulate, 80–110 μm diam. and conidial filament 8–10.5 μm wide in the broadest part (\( \bar{x} \) = 90 × 9 μm, n = 20), tapering to 4–5 μm wide near apex and base, 565–705 μm long, 60–74-septate, constricted at septa, coiled 2–2½ times, becoming loosely coiled in water, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 12 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Hechi City, on submerged decaying wood in a freshwater stream, 18 May 2016, Yong-Zhong Lu, XSL04 (GZAAS 16–0083, holotype), ex-type living culture, MFLUCC 17–0051, GZCC 16–0071; Ibid., XSL03–2 (GZAAS 16–0082, paratype), living culture, GZCC 16–0070; Ibid., XSL06 (GZAAS 16–0085, paratype), living culture, GZCC 16–0073; Ibid., XSL08–3 (GZAAS 16–0087, paratype), living culture, GZCC 16–0075.

Notes: Morphologically, Helicomyces hyalosporus resembles H. roseus in conidiophore and conidia characters, but can be differentiated by its larger conidial diameter and wider conidial filaments (80–110 × 8–10.5 μm vs. 25–60 × 2.5–6 μm) (Linder 1929; Goos 1985). Phylogenetically, four isolates of H. hyalosporus formed one clade and shares a sister relationship to H. torquatus and H. chiayiensis with high bootstrap support (Fig. 2), which indicates that they are distinct species.


Helicomyces torquatus L.C. Lane & Shearer, Mycotaxon 19: 291 (1984)

Index Fungorum: IF 106861; Facesoffungi number: FoF 04724; Fig. 28

Fig. 28
figure 28

Helicomyces torquatus (MFLU 17–1171, reference specimen). a Colony on decaying wood. b, c Conidiogenous cell with attached conidia. d Conidiophores. e, f Conidiogenous cells. g–k Conidia. l, m Colonies on MEA from above and below. Scale bars: a = 500 µm, b–d, g–k = 50 µm, e, f = 20 µm

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Reference specimen: MFLU 17–1171

Possible distribution: Australia, Cuba, Malaysia, Mexico, New Zealand, Panama, Thailand▲.

Habitat: Aquatic, Terrestrial.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium mostly immersed, partly superficial, composed of branched, septate hyphae, hyaline at first, becoming subhyaline to pale brown, with masses of crowded, cottony conidia. Conidiophores macronematous, mononematous, erect, cylindrical, branched or unbranched, 0–3-septate, arising as lateral branches from creeping hyphae, 20–75 μm long, 4–5 μm wide, hyaline, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, 10–15 μm long, 4–5 μm wide, hyaline, smooth-walled. Conidia solitary, acrogenous, helicoid, dry, attached eccentrically and seceding schizolytically, rounded at tip, end cells broadly spathulate, the basal cell bearing a flattened attachment scar, 55–90 μm in diam. and conidial filament 6.5–8.5 μm wide in the broadest part (\( \bar{x} \) = 75 × 7.5 μm, n = 20), tapering to 3.5–4 μm wide near apex and base, 450–630 μm long, indistinctly multi-septate, coiled 2½–3¾ times, becoming loosely coiled in water, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, circular, with flat surface, edge entire, reaching 10 mm in 2 weeks at 28 °C, pale brown to brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Phang-Nga, Thap Put, Tham Thong Lang, on submerged decaying wood in a freshwater stream, 17 December 2015, Saranyaphat Boonmee, TL01–1 (MFLU 17–1171, reference specimen designated here; HKAS 100724), living cultures, MFLUCC 16–0217, TBRC 8904.

Notes: Lane and Shearer (1984) pointed out that Helicomyces torquatus differs from all other Helicomyces species by its large-sized conidium with a spathulate basal end cells and guttulate conidial cells filled with large oil droplets. Goos (1989) reexamined the type dried culture specimen of H. torquatus and accepted the description of Lane and Shearer (1984). Zhao et al. (2007) reported a new record of H. torquatus from China, even they found that the conidial size of their new isolate was smaller than previous studies. They identified their collection (HMAS 98748) as H. torquatus, as had doubts that the large-sized conidia given by previous studies were mainly measured on loosely coiled or uncoiled conidia. Despite that its morphology differed from previous studies in having abundant stalked sclerotia and each conidium had several secondary conidia, Kuo and Goh (2018b) identified their new collection (NCYU-K4-1) as H. torquatus and discussed its phylogenetic relationships (strain no. BCRC FU30844). However, our phylogenetic result shows that the isolate BCRC FU30844 clusters within Tubeufia. Furthermore, our newly obtained isolate morphologically corresponds to those described by Lane and Shearer (1984) and Goos (1989), including the morphology of conidiophore and conidia, as well as their sizes are also identical. Therefore, our new isolate is undoubtedly H. torquatus, and this is the first record of this species in Thailand. Since the holotype and paratype deposited in NYBG are available but lack molecular data, we designate our newly collected specimen (MFLU 17–1169) as a reference specimen.

We suspect the specimen HMAS 98748 described by Zhao et al. (2007) is not H. torquatus, but we retain its status because of a lack of taxonomic information to exclude it.

Tsui et al. (2006) provided ITS and LSU sequence data for H. torquatus (CBS 189.95) but did not describe its morphological features. However, our phylogenetic result showed that the strain CBS 189.95 grouped within Neohelicosporium and distant from our new isolate of MFLUCC 16–0217 (Fig. 2). In addition, the morphology of H. torquatus obviously differs from Neohelicosporium species in conidiophore, conidiogenous cells and conidia. Thus, we consider that CBS 189.95 is misidentified. Accordingly, we treat CBS 189.95 as an unidentified species and named as Neohelicosporium sp. (CBS 189.95), as this isolate grouped within Neohelicosporium but lacks morphological information. New collections and molecular data are needed to resolve its taxonomy.

New combinations of Helicomyces

Helicomyces chiayiensis (C.H. Kuo & Goh) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicoma chiayiense C.H. Kuo & Goh, Mycol. Progr. 17(5): 561 (2018)

Index Fungorum: IF 554853; Facesoffungi number: FoF 04799

Type: CHINA, Taiwan, Chiayi County, Juchi Township, on debarked wood submerged in a freshwater stream, 5 Feb. 2017, Chang-Hsin Kuo, NCYU-K3-1 (TNM F31002, deposited at National Museum of Natural Science, Taichung, Taiwan).

Known distribution: China (Taiwan).

Habitat: Aquatic.

Description: For a complete description of this taxon see Kuo and Goh (2018a, as Helicoma chiayiense).

Notes: This taxon was described as Helicoma chiayiense by Kuo and Goh (2018a). However, our phylogenetic analyses show that this taxon groups within the genus Helicomyces and shares a sister relationship to Helicomyces torquatus with good bootstrap support (96% MLBS, 1.00 PP) (Fig. 2). Furthermore, its morphology also fits well within Helicomyces species than Helicoma.

Other accepted Helicomyces species

Helicomyces ambiguus (Morgan) Linder, Ann. Mo. bot. Gdn 16: 273 (1929)

≡ Helicoma ambiguum Morgan, J. Cincinnati Soc. Nat. Hist. 15: 48 (1892)

≡ Helicosporium ambiguum (Morgan) Sacc., Syll. fung. (Abellini) 11: 638 (1895)

Index Fungorum: IF 256615

Possible distribution: China (Hainan), Japan, New Zealand, USA (Ohio).

Habitat: Terrestrial.

Notes: Linder (1929) transferred Helicoma ambiguum to Helicomyces ambiguus. Tubaki (1958) reported a new record of H. ambiguus. Goos (1985) reexamined the type specimen of H. ambiguus and accepted Linder’s treatment. Zhao et al. (2007) reported a new record of H. ambiguus from China but he mentioned their new collection was doubtful of this species.


Helicomyces denticulatus G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 338 (2007)

Index Fungorum: IF 510623

Known distribution: China (Hainan).

Habitat: Terrestrial.

Notes: Helicomyces denticulatus was introduced by Zhao et al. (2007) and it is characterized by a combination of short and stout conidiophores formed laterally on creeping hyphae and denticulate conidiogenous cells.


Helicomyces hyderabadensis P. Rag. Rao & D. Rao [as ‘hyderabadense’], Mycopath. Mycol. appl. 24(1): 28 (1964)

Index Fungorum: IF 331774

Possible distribution: Brazil, China (Hainan), India.

Habitat: Terrestrial.

Notes: Helicomyces hyderabadensis was introduced by Rao and Rao (1964). Pirozynski (1972) noted that this taxon was quite similar to Helicomyces roseus. Goos (1985) described this taxon based on the description of Rao and Rao (1964). Zhao et al. (2007) reported a new record of H. hyderabadensis from China.


Helicomyces louisianensis Goos, Mycologia 77(4): 612 (1985)

Index Fungorum: IF 105343

Possible distribution: China (Guangdong), USA (Louisiana).

Habitat: Terrestrial.

Notes: Goos (1985) indicated that multiple coiling (with up to ten coils) of the helicoid conidia of Helicomyces louisianensis makes it easily distinguishable from other known species. Zhao et al. (2007) reported a new record of H. louisianensis.


Helicomyces macrofilamentosus Matsush., Matsush. Mycol. Mem. 3: 11 (1983)

Index Fungorum: IF 108044

Possible distribution: China (Guangdong, Hainan, Taiwan), Mexico.

Habitat: Terrestrial.

Notes: Matsushima (1983) reported that this taxon corresponds to Helicomyces in having short conidiophores and hygroscopic helicoid conidia. Zhao et al. (2007) indicated that H. macrofilamentosus is similar to H. roseus but can be distinguished by its larger conidial filaments. However, we noted that the conidia described by Zhao et al. (2007) has a larger conidial diameter and the number of conidial septa is more than those described by Matsushima (1983), i.e. 55–70 μm vs. 35–55 μm diam., up to 65-septate vs. 25–40-septate, and its conidial filaments are obviously smaller than those described by Matsushima (1983) (5–6.5 μm vs. 6–12 μm). Hence, we consider that they are distinct species. Furthermore, Kodsueb et al. (2006) provided the LSU sequence data for H. macrofilamentosus (HKUCC 10235), but our phylogenetic result shows that H. macrofilamentosus (HKUCC 10235) grouped within Neohelicosporium. However, its morphology does not correspond to Neohelicosporium at all. This sequence data does not match those of H. macrofilamentosus, and we treat the isolate (HKUCC 10235) as an unidentified Neohelicosporium species (Named Neohelicosporium sp. HKUCC 10235) because Kodsueb et al. (2006) did not describe its morphological features. Therefore, we do not synonymize this taxon but provisionally retained it as a valid Helicomyces species pending new collections and molecular evidence.


Helicomyces roseus Link, Mag. Gesell. Naturf. Freunde, Berlin 3(1–2): 21 (1809)

= Helicomyces albus Preuss, Linnaea 25: 725, 1852

= Helicomyces elegans Morgan, Cinci. Soc. Nat. Hist. J. 15: 45, 1892

= Helicomyces clarus Morgan, Cinci. Soc. Nat. Hist. J. 15: 44, 1892

= Helicomyces fuscopes Linder. Ann. Missouri Bot. Gard. 18: 15–16, 1931

Index Fungorum: IF 237696

Possible distribution: Austria, Belgium, Bermuda, Brazil, Canada, China (Hainan, Guangdong), Colombia, Cuba, Denmark, England, Estonia, France, Germany, Grenada, India, Italy, Japan, Malaysia, Mexico, New Zealand, Okinawa, Portugai, Switzerland, Tasmania, USA (Hawaii, Indiana).

Habitat: Aquatic, Terrestrial.

Notes: Helicomyces roseus is the type species of Helicomyces. This species had been well studied based on morphology but its phylogenetic relationship is still confused. Linder (1929), Seaver and Waterston (1940), Rao and Rao (1964) (as Helicomyces fuscopes), Matsushima (1971, 1975), Pirozynski (1972) (as H. fuscopes), Goos (1980) (as H. fuscopes), Goos (1985), Zhao et al. (2007) and Boonmee et al. (2014) have described its morphological characteristics. Tsui et al. (2006, 2007) and Tsui and Berbee (2006) provided ITS, LSU and SSU sequence data for two “H. roseus” isolates (CBS 283.51 and BCC 8808), however, these two isolates segregated in distinct clades, which implied that they should have been wrongly identified. Kodsueb et al. (2006) provided LSU sequence data for one “H. roseus” isolate (BCC 3381). Boonmee et al. (2014) considered that the clade included the isolate (CBS 283.51) represented the genus Helicomyces, and they also found that the isolates of BCC 3381 and BCC 8808 appeared in distinct clades within Tubeufia, thus, they renamed them as Tubeufia roseus but did not formally synonymize them. Luo et al. (2017) reported five new isolates of H. roseus with phylogenetic data, but we reappraise them as Pseudohelicomyces hyalosporus based on phylogenetic analyses and morphological evidence in this study (see Pseudohelicomyces hyalosporus).

There are many isolates and specimens identified as Helicomyces roseus but its phylogenetic relationship is still unclear, therefore, an epitype or a reference specimen is needs to be designated. However, we are not able to resolve this problem here because lack of enough evidence. In this paper, we find that our new species Helicomyces hyalosporus resembles H. roseus in conidiophore and conidial characters, the only difference between them is that the larger conidial diameter and wider conidial filaments (80–110 × 8–10.5 μm vs. 25–60 × 2.5–6 μm) (Linder 1929; Goos 1985). Furthermore, all taxa in Clade 4 correspond well to Helicomyces in both conidiophores and conidial morphology. Therefore, even the phylogenetic relationship of the type species Helicomyces roseus is unclear, we consider that Clade 4 can represent Helicomyces sensu stricto.


Helicomyces scandens Morgan, J. Cincinnati Soc. Nat. Hist. 15: 42 (1892)

= Helicostilbe helicina Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. I 111: 1028 (1902)

Index Fungorum: IF 237240

Possible distribution: Austria, Canada, Chile, China (Yunnan), USA (Connecticut, Ohio, Massachusetts, Missouri).

Habitat: Terrestrial.

Notes: Helicomyces scandens is characterized by the synnematous structure formed by anastomosing mycelium and bristle-like setae (Morgan 1892). Linder (1929) synonymized Helicostilbe helicina under H. scandens. Sutton (1973) and Goos (1985) have described this taxon. Zhao et al. (2007) reported a new record of H. scandens from China, and pointed out that the conidia of their new specimen were relatively smaller than those described by Goos (1985) (9–12.5 μm diam. vs. 15–35 μm diam.). Moreover, Tsui et al. (2006) provided LSU sequence data for H. scandens (CBS 113453) but they simultaneously mentioned that it might be related to Hymenoscyphus sp. (Leotiomycetes) and unrelated to Tubeufiaceae. Therefore, the sequence of H. scandens (CBS 113453) is doubtful.


Helicomyces tenuis Speg., Anal. Mus. nac. B. Aires, Ser. 3 13: 423 (1911)

Index Fungorum: IF 247833

Possible distribution: Argentina, Britain, New Zealand, Surinam.

Habitat: Terrestrial.

Notes: Linder (1929) pointed out that Helicomyces tenuis differs from Helicomyces roseus only as having a smaller diameter of the conidial filament. Goos (1985) reexamined the type specimen of H. tenuis and gave a detailed description, and retained H. tenuis as a valid Helicomyces species.

Excluded Helicomyces species

Helicomyces radicatus Teng, Contr. Biol. Lab. Sci. Soc. China, Bot. Ser.: 26 (1932)

Index Fungorum: IF 276037

Notes: This is a very poorly studied species. There is no study has been reported since the species was described by the author, and no illustration and description are available for this fungus. Therefore, we treat it as a doubtful species.


Helicosporium Nees, Syst. Pilze (Würzburg): 68 (1817)

Index Fungorum: IF 8484

Saprobic on decaying woody substrate. Sexual morph Ascomata superficial, solitary, scattered, globose-subglobose, bright yellow brown to yellow orange, collapsing when dry, darkened near ostiole. Peridium comprising several layers, outer layers comprising bright yellow cells of textura angularis, inner layers comprising yellow cells of textura prismatica. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindric-clavate, apedicellate, thickened at apex, with an acute ocular chamber. Ascospores 2–3-seriate, fusiform, tapering towards narrowly subacute ends, multi-septate, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, pale yellow to yellow green. Mycelium composed of partly immersed, partly superficial, brown to dark brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, erect, setiferous, cylindrical, septate, brown to dark brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, mostly discrete, determinate, denticulate, arising laterally from the lower parts of conidiophores as tiny tooth-like protrusions or bladder-like protrusions, hyaline to pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, indistinctly multi-septate, smaller than 25 μm diam., conidial filament smaller than 4 μm wide, guttulate, hyaline to yellow green, smooth-walled.

Type species: Helicosporium vegetum Nees, Syst. Pilze (Würzburg): 68 (1817)

Notes: The genus Helicosporium was established by Nees (1817) based on the type species H. vegetum. Linder (1929) redefined the generic concepts of the overlapping genera Helicomyces, Helicosporium and Helicoma, and separated Helicomyces and Helicosporium from Helicoma on the basis of the relatively thick-walled, non-hygroscopic conidia found in Helicoma, and the thin-walled, hygroscopic conidia found in the former two genera. Goos (1989) reviewed the status of all known Helicosporium species and redefined the generic concept including species with hyaline conidia whose filaments do not exceed 3 μm diam. Lu et al. (2018) introduced a new helicosporous genus, Neohelicosporium, whose morphology resembles Helicosporium but phylogenetically is a distinct genus. With more phylogenetic and morphology data in this study, we reviewed all known Helicosporium species and compared them to our newly obtained isolates, and redefined the generic concept of Helicosporium including species of those whose colonies on the substratum superficial are pale yellow to yellow green, conidiophores are setiferous, brown to dark brown, conidiogenous cells are discrete, determinate, denticulate, arising laterally from the lower parts of conidiophores as tiny tooth-like protrusions or bladder-like protrusions, and conidia are pleurogenous, helicoid, smaller than 25 μm diam., conidial filaments do not exceed 4 μm thick, hyaline to yellow green.

In this study, we accept 13 species within Helicosporium including our five new species, and exclude 25 species from this genus (shown in Table 3). Two misidentifications (H. vegetum BCC 3332 and H. vegetum BCC 8125) are reappraised and revised based on phylogenetic analyses.


Helicosporium aquaticum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554854; Facesoffungi number: FoF 04725; Fig. 29

Fig. 29
figure 29

Helicosporium aquaticum (MFLU 17–1148, holotype). a Colony on decaying wood. b Conidiophore with attached conidia. c, d Conidiogenous cells. e–g Conidiophores. h–l Conidia. m, n Colonies on PDA from above and below. o Umbonate colony surface on PDA from above. Scale bars: a = 100 µm, b = 20 µm, c, d, h–l = 10 µm, e–g = 50 µm

Full size image

Holotype: MFLU 17–1148

Etymology: “aquaticum” referring to aquatic habitat of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, yellow green. Mycelium composed of partly immersed, partly superficial, pale brown to brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, setiform, cylindrical, unbranched, septate, 95–170 μm long, 2–4 μm wide at bottom, 1–2 μm wide at apex, pale brown to brown, smooth-walled. Conidiogenous cells denticulate, holoblastic, monoblastic, discrete, determinate, arising laterally from lower portion of the conidiophores as tiny tooth-like protrusions, hyaline, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 10–14 μm diam. and conidial filament 1–2 μm wide (\( \bar{x} \) = 12 × 1.5 μm, n = 20), 70–90 μm long, tightly coiled 2½–3½ times, becoming loosely coiled or uncoiled in water, indistinctly multi-septate, guttulate, hyaline to yellowish, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with umbonate surface, edge entire, reaching 6 mm in 2 weeks at 28 °C, pale brown to brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Rayong, Klaeng, Thang Kwian, on submerged decaying wood in a freshwater stream, 24 April 2017, Yong-Zhong Lu, RK04 (MFLU 17–1148, holotype; HKAS 100819, isotype), ex-type living cultures, MFLUCC 17–2008, TBRC.

Notes: Morphologically, Helicosporium aquaticum resembles H. vegetum and H. setiferum in conidia and conidiophores. Helicosporium aquaticum can be recognized from H. vegetum by its different number of coils and different conidia and conidiophores colour, and from H. setiferum by its smaller conidia size. Phylogenetically, H. aquaticum shares a sister relationship to H. setiferum with high bootstrap support (100% MLBS, 1.00 PP) (Fig. 2), but they are distinct species.


Helicosporium flavisporum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554855; Facesoffungi number: FoF 04726; Figs. 30 and 31

Fig. 30
figure 30

Helicosporium flavisporum (MFLU 17–1105, holotype). a Colony on decaying wood. b–e Conidiophores. f–g Conidiogenous cells. h–n Conidia. o, p Colonies on PDA from above and below. Scale bars: a = 100 µm, b–e = 50 µm, f–n = 10 µm

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Fig. 31
figure 31

Asexual morph of Helicosporium flavisporum from ex-type cultures. a Hyphae in PDA medium. b–f Conidiophores. g–n Conidia. Scale bars: a = 50 µm, b–f = 20 µm, g–n = 10 µm

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Holotype: MFLU 17–1093

Etymology: “flavisporum” referring to bright yellow helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, yellow to brown. Mycelium composed of partly immersed, partly superficial, brown, septate, branched hyphae, with masses of crowded, glistening yellow conidia. Conidiophores macronematous, mononematous, cylindrical, unbranched, septate, 130–180 μm long, 3.5–6 μm wide, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, discrete, determinate, arising laterally from lower portion of the conidiophores as tiny bladder-like protrusions, 3–9 μm long, 2–3 μm diam., with each bearing 1–2 tiny sporogenous conidiogenous loci, hyaline to pale yellow, smooth-walled. Conidia pleurogenous, helicoid, rounded at tip, 12–15 μm diam. and conidial filament 1–2 μm wide (\( \bar{x} \) = 13 μm diam., 1.5 μm wide, n = 20), 100–110 μm long, tightly coiled 2½–3½ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline to yellowish, smooth-walled. Asexual morph (found from cultures) Hyphomycetous, helicosporous. Conidiophores macronematous, mononematous, irregular cylindrical, branched, septate, 15–40 μm long, 2–4.5 μm wide, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, terminal or intercalary, irregular cylindrical, sympodial, with denticles, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, 12–15 μm diam. and conidial filament 1–2 μm wide (\( \bar{x} \) = 13 × 1.5 μm, n = 20), 90–110 μm long, tightly coiled 2½–3½ times, becoming loosely coiled in water, rounded at tip, indistinctly multi-septate, guttulate, hyaline to bright yellow, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, with flat surface, edge undulate, reaching 29 mm in 6 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth. Producing hyaline to yellow helicoid conidia after 6 weeks (Fig. 30).

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 25 March 2017, Yong-Zhong Lu, CR31 (MFLU 17–1105, holotype; HKAS 100775, isotype), ex-type living cultures, MFLUCC 17–2020, TBRC.

Notes: Morphologically, Helicosporium flavisporum resembles H. decumbens, H. neesii and H. vesicarium in conidiophores, conidiogenous cells and conidia but can be distinguished by their size. Helicosporium flavisporum differs from H. decumbens by its larger conidia (12–15 × 1–2 μm vs. 6–9 × 0.75–1.5 μm) and different number of coils (2½–3½ times vs. 1–2 times) (Linder 1929; Goos 1989), differs from H. neesii by its shorter conidiophores (130–180 vs. 350–400 μm, up to 600 μm) (Moore 1957; Goos 1989, as Helicosporium virescens), differs from H. visicarium by its longer conidiophores (130–180 μm vs. 65–120 μm) and yellow conidia (this study). One interesting discovery on this fungus is that its asexual morph produced from cultures differs from those obtained from natural decaying woody substrate in conidiophores and conidiogenous cell features. Phylogenetically, H. flavisporum shares a sister relationship to H. visicarium with good bootstrap support (100% MLBS, 1.00 PP) (Fig. 2).


Helicosporium setiferum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554856; Facesoffungi number: FoF 04727; Fig. 32

Fig. 32
figure 32

Helicosporium setiferum (MFLU 17–1134, holotype). a, b Colony on decaying wood. c–f Conidiophores. g Conidiogenous cells. h–m Conidia. n, o Colonies on PDA from above and below. Scale bars: a, b = 100 µm, c–f = 50 µm, g = 20 µm, h–m = 10 µm

Full size image

Holotype: MFLU 17–1134

Etymology: “setiferum” referring to setiferous-like conidiophores of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, yellow green. Mycelium composed of partly immersed, partly superficial, pale brown to brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, setiform, cylindrical, mostly unbranched, occasionally branched, septate, 125–320 μm long, 3–5 μm wide at bottom, 1–2 μm wide at apex, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, monoblastic, discrete, determinate, denticulate, arising laterally from the conidiophores as tiny tooth-like protrusions, hyaline. Conidia solitary, pleurogenous, helicoid, rounded at tip, 13–21 μm diam. and conidial filament 1–2 μm wide (\( \bar{x} \) = 16 × 1.7 μm, n = 20), 100–130 μm long, tightly coiled 2½–3½ times, becoming loosely coiled or uncoiled in water, indistinctly multi-septate, guttulate, hyaline to yellowish, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge undulate, reaching 14 mm in 3 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW04 (MFLU 17–1134, holotype; HKAS 100805, isotype), ex-type living cultures, MFLUCC 17–1994, TBRC; THAILAND, Rayong, Klaeng, Thang Kwian, on submerged decaying wood in a freshwater stream, 24 April 2017, Yong-Zhong Lu, RK02 (MFLU 17–1146 = HKAS 100817, paratype), living culture, MFLUCC 17–2006; Ibid., RK03 (MFLU 17–1147 = HKAS 100818, paratype), living culture, MFLUCC 17–2007.

Notes: Morphologically, Helicosporium setiferum resembles H. aquaticum in conidia and conidiophores, but can be recognized by its larger sized conidia. Phylogenetically, our three new isolates cluster together with two H. vegetum isolates (BCC 3332 and BCC 8125) provided by Tsui et al. (2006). These two isolates must have been misidentified because they are apart from the ex-type strain of H. vegetum (CBS 941.72). We also noted that isolates of MFLUCC 17–1994 and MFLUCC 17–2006 with BCC 8125 formed one clade with good bootstrap support (93% MLBS, 1.00 PP) (Fig. 2), which is slightly phylogenetically divergent from MFLUCC 17–2007 and BCC 3332. Following the recommendations of Jeewon and Hyde (2016) for delimitation of new species, we looked into pairwise dissimilarities of DNA sequences and noted that there are 1 bp (base pair), 1 bp, 9 bp and 2 bp nucleotide differences in ITS, LSU, RPB2 and TEF1α between MFLUCC 17–2007 and MFLUCC 17–1994, respectively, which may explain a close phylogenetic relatedness between them and their slight phylogenetic divergence from the other isolates. However, we could not identify any morphological features to separate our three isolates and those fewer gene base pair changes are not enough to indicate they are different species. Hence, we identify our three isolates as Helicosporium setiferum. Despite a lack of morphological descriptions, we identify BCC 3332 and BCC 8125 with our new isolates as the same species based on their identical DNA sequence data.


Helicosporium vesicarium Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554857; Facesoffungi number: FoF 04728; Fig. 33

Fig. 33
figure 33

Helicosporium vesicarium (MFLU 17–1093, holotype). a Colony on decaying wood. b–e Conidiophores. f–g Conidiogenous cells. h–l Conidia. m Germinating conidium. n, o Colonies on PDA from above and below. Scale bars: a = 100 µm, b–e = 50 µm, f–m = 10 µm

Full size image

Holotype: MFLU 17–1093

Etymology: “vesicarium” referring to bladder-like protrusions conidiogenous cells of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, yellow green. Mycelium composed of partly immersed, partly superficial, pale brown to brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, unbranched, septate, 65–120 μm long, 3.5–5 μm wide, pale brown to dark brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, discrete, determinate, arising laterally from lower portion of the conidiophores or creep hyphae as tiny bladder-like protrusions, 3–9 μm long, 2–3.5 μm diam., with each bearing 1–2 tiny conidiogenous loci, hyaline to pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 13–18 μm diam. and conidial filament 1.5–3 μm wide (\( \bar{x} \) = 16 × 2 μm, n = 20), 100–150 μm long, tightly coiled 2½–3¾ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline to yellowish, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, circular, with flat surface, edge entire, reaching 19 mm in 3 weeks at 28 °C, brown to dark brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR11 (MFLU 17–1093, holotype; HKAS 100763, isotype), ex-type living cultures, MFLUCC 17–1795, TBRC.

Notes: Morphologically, Helicosporium vesicarium resembles H. decumbens, H. flavisporum and H. neesii in conidiophores and conidiogenous cells as well as conidia but can be distinguished by their size. Helicosporium vesicarium differs from H. decumbens by its larger conidia (13–18 × 1.5–3 μm vs. 6–9 × 0.75–1.5 μm) and different number of coils (2½–3¾ vs. 1¾–2 times) (Linder 1929; Goos 1989), differs from H. flavisporum by its shorter conidiophores (65–120 μm vs. 130–180 μm) and different conidia colour, differs from H. neesii by its shorter conidiophores (65–120 vs. 350–400 μm, up to 600 μm) (Moore 1957; Goos 1989, as Helicosporium virescens). Phylogenetically, H. visicarium shares a sister relationship to H. flavisporum with good bootstrap support (Fig. 2). There are five noticeable nucleotide differences among the 484 nucleotides ITS sequences between H. visicarium (MFLUCC 17–1795) and H. flavisporum (MFLUCC 17–2020), which support that they are distinct species.


Helicosporium viridiflavum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554858; Facesoffungi number: FoF 04729; Fig. 34

Fig. 34
figure 34

Helicosporium viridiflavum (MFLU 17–1150, holotype). a Colony on decaying wood. b–d Conidiophores. e–i Conidiogenous cells. j–p Conidia. q, r Colonies on PDA from above and below. Scale bars: a = 100 µm, b–d = 50 µm, e–p = 10 µm

Full size image

Holotype: MFLU 17–1150

Etymology: “viridiflavum” referring to yellow green helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, yellow green. Mycelium composed of partly immersed, partly superficial, pale brown to brown, septate, branched hyphae, with masses of crowded, glistening yellow green conidia. Conidiophores macronematous, mononematous, cylindrical, mostly unbranched, septate, 250–425 μm long, 3–4 μm wide at bottom, 1–2 μm wide at apex, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, determinate, denticulate, arising laterally from the conidiophores as tiny tooth-like protrusions, hyaline, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 20–23 μm diam. and conidial filament 2–3.5 μm wide (\( \bar{x} \) = 21 × 3 μm, n = 20), 105–140 μm long, tightly coiled 2–2½ times, becoming loosely coiled in water, guttulate, 13–16-septate, hyaline to yellow green, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia after 72 h. Colonies growing on PDA, circular, with umbonate surface, edge entire, very slowly growing, reaching 15 mm in 3 months at 28 °C, pale brown to brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on decaying wood in a mountain, 26 April 2017, Yong-Zhong Lu, TM03 (MFLU 17–1150, holotype; HKAS 100821, isotype), ex-type living cultures, MFLUCC 17–2336, TBRC.

Notes: Morphologically, Helicosporium viridiflavum is similar to H. aquaticum and H. setiferum in having yellow green colonies on natural decaying woody substrate, but can be easily recognized by its longer conidiophores and thicker conidia. Besides, one unusual characteristic between H. viridiflavum and other helicosporous hyphomycetes that we found is, that H. viridiflavum growing extremely slow, its conidia germinating on water agar took more than 72 h while others at most 24 h, and its colonies only reached 15 mm in PDA medium in 3 months at 28 °C while others reaching 15 mm not exceeding 3 weeks. Phylogenetically, H. viridiflavum shares a sister relationship to Helicosporium flavum but they are distinct species (Fig. 2).

Other accepted Helicosporium species

Helicosporium albidum Grove, J. Bot., Lond. 24: 204 (1886)

Index Fungorum: IF 236844

Possible distribution: Belgium, Britain (Birminghan).

Habitat: Terrestrial.

Notes: Helicosporium albidum was introduced by Grove (1886). Linder (1929) accepted Grove’s identification. Moore (1955) regarded it as a “Species Inquirendae’ as the material of the fungus was unavailable and that the description was inadequate. Goos (1989) accepted Moore’s evaluation. We accepted Grove (1886) and Linder (1929), and treat this fungus as a valid Helicosporium species based on its morphological similarities to Helicosporium.


Helicosporium decumbens Linder, Ann. Mo. bot. Gdn 16: 285 (1929)

Index Fungorum: IF 262880

Possible distribution: Austria, Brazil.

Habitat: Terrestrial.

Notes: This taxon was introduced by Linder (1929). Goos (1989) also studied this taxon. We accept both Linder (1929) and Goos (1989) as its morphology correspond to those Helicosporium species circumscribed based on phylogeny.


Helicosporium flavum Brahaman., Y.Z. Lu, Boonmee & K.D. Hyde, Mycosphere 8(7): 931 (2017)

Index Fungorum: IF 553180

Known distribution: Thailand.

Habitat: Aquatic.

Notes: This taxon was introduced by Brahamanage et al. (2017) based on morphology and phylogenetic evidence. Its asexual morph was found from the cultures (the culture was obtained form the sexual morph), and it is morphologically distinct to other phylogenetically recognised Helicosporium species by its acropleurogenous conidia, as well as the wider and shorter conidiophores.


Helicosporium luteosporum Y.Z. Lu, Boonmee & K.D. Hyde, Phytotaxa 319(3): 248 (2017)

Index Fungorum: IF 552663

Known distribution: Thailand.

Habitat: Terrestrial.

Notes: This taxon was introduced by Lu et al. (2017a) based on morphological and phylogenetic evidence.


Helicosporium melghatianum Hande, Journal of Mycology and Plant Pathology 40(2): 237 (2010)

Index Fungorum: IF 548216

Known distribution: India.

Habitat: Terrestrial.

Notes: Helicosporium melghatianum was introduced by Dharkar et al. (2010). Its morphology corresponds to Helicosporium.


Helicosporium murinum Goos, Mycologia 81(3): 367 (1989)

= Helicosporium griseum (Bonord.) Sacc., Syll. Fung. 4: 559, 1886 [non Helicosporium griseum Berk. & M.A. Curtis, 1874].

≡ Helicoma griseum Bonord., Handb. Allgem. mykol. (Stuttgart): 74 (1851)

Index Fungorum: IF 125393

Possible distribution: Argentina, Austria, Brazil, Canada (British Columbia), Cuba, Malaysia, USA (Iowa, Massachusetts, New York).

Habitat: Terrestrial.

Notes: Linder (1929), Goos (1989) and Zhao et al. (2007) have studied this taxon. Its morphology fits to Helicosporium.


Helicosporium neesii R.T. Moore, Mycologia 49: 582 (1957)

Index Fungorum: IF 298246

Known distribution: USA (New Jersey).

Habitat: Terrestrial.

Notes: Helicosporium neesii was introduced by Moore (1957). Goos (1989) reexamined its type material and synonymized it under Helicosporium virescens. Morgan-Jones and Goos (1992) synonymized H. virescens under Chloridium virescens, and H. neesii under Helicosporium vegetum. However, we found that H. neesii differs from H. vegetum in conidiophores and conidiogenous cells, which are important characteristics to identify Helicosporium species, therefore, we restored Helicosporium neesii as a valid Helicosporium species.


Helicosporium vegetum Nees, Syst. Pilze (Würzburg): 68 (1816) [1816–1817]

= Helicotrichum vegetum (Nees) Wallr., Fl. crypt. Germ. (Norimbergae) 2: 161 (1833)

= Helicosporium fuckelii Fresen., Beitr. Mykol. 3: 101 (1863)

= Sphaeria cerea Berk. & M.A. Curtis, Grevillea 4(no. 31): 108 (1876)

= Calonectria cerea (Berk. & M.A. Curtis) Sacc., Syll. fung. (Abellini) 2: 551 (1883)

= Dialonectria cerea (Berk. & M.A. Curtis) Cooke, Grevillea 12(no. 64): 111 (1884)

= Ophionectria cerea (Berk. & M.A. Curtis) Ellis & Everh., N. Amer. Pyren. (Newfield):

118 (1892)

= Helicosporium olivaceum Peck, Ann. Rep. N.Y. St. Mus. nat. Hist. 27: 102 (1875)

= Helicomyces vegetus (Nees) Pound & Clem., Minn. bot. Stud. 1(Bulletin 9): 659 (1896)

= Tubeufia cerea (Berk. & M.A. Curtis) Höhn., Sber. Akad. Wiss. Wien, Math.-naturw.

Kl., Abt. 1 128: 562 (1919)

Index Fungorum: IF 145573

Possible distribution: Worldwide.

Habitat: Terrestrial.

Notes: Helicosporium vegetum was introduced by Nees (1817) as the type species of Helicosporium. Linder (1929) provided a detailed description and illustration for this species. Booth (1964), Samuels et al. (1979) and Barr (1980) reported the asexual morph of Tubeufia cerea near its ascomata, and identified the asexual morph as H. vegetum. Goos (1989) synonymized H. vegetum under H. virescens. Morgan-Jones and Goos (1992) synonymized H. virescens under Chloridium virescens, and H. neesii under H. vegetum. Zhao et al. (2007) accepted Goos’s treatment and reported a new record of H. virescens. We accepted the evaluation of Morgan-Jones and Goos (1992) as they pointed out that H. virescens and Chloridiium virescens were unacceptable nomenclatural situation, but we restored H. neesii as a valid Helicosporium species based on its distinct conidiophores and conidiogenous cells morphology.

Besides, Spatafora et al. (2006) provided LSU and TEF1α sequence data for Tubeufia cerea (CBS 254.75) and Tsui et al. (2006) provided the ITS and LSU sequence data for T. cerea (NBRC 9014) and Helicosporium vegetum. Boonmee et al. (2014) reexamined the specimen of H. vegetum (BPI 447464) and Tubeufia cerea (BPI 1107327), and linked the sexual morph with asexual morph based on phylogenetic evidence. However, our phylogenetic analyses show that Tubeufia cerea (NBRC 9014) is apart from the other H. vegetum strains with high bootstrap support (Fig. 2). Following Jeewon and Hyde’s (2016) recommendations on species delimitation for new species, we looked into pairwise dissimilarities of DNA sequences and noted that there are 20 noticeable nucleotide differences among the 508 nucleotides ITS sequences between NBRC 9014 and other H. vegetum strains, which indicate that they are distinct species. Because the strain NBRC 9014 lacks morphological descriptions, we renamed it as Helicosporium sp. in this study.

Excluded Helicosporium species

Helicosporium gracile (Morgan) Linder, Ann. Mo. bot. Gdn 16: 281 (1929)

≡ Helicomyces gracilis Morgan, J. Cincinnati Soc. Nat. Hist. 15: 40 (1892)

Index Fungorum: IF 266303

Notes: This taxon was introduced as Helicomyces gracilis by Morgan (1892). Linder (1929) synonymized it under Helicosporium gracile. Goos (1989) reexamined and described this taxon. Zhao et al. (2007) reported a new record from China. However, we compared these four previous studies of this species and found that they are morphologically different to each other. The illustration provided by Morgan (1892) shows that the upper part of conidiophores is sterile and all of conidia are pleurogenous. Linder (1929) showed that conidia are pleuroacrogenous and lack sterile features in the upper part of conidiophores. Zhao et al. (2007) reported it was pleuroacrogenous conidia and also lacking sterile features in upper part of conidiophores. Besides, the conidial size provided by Zhao et al. (2007) (30–40 × 2–2.5 μm) were obviously lager than others (10–15 × 1–1.5 μm). Thus, we suspect these previous studies are probably different species. When we compared these four descriptions to our new collections and other known Helicosporium species, all of them do not correspond to Helicosporium with respect to their pleuroacrogenous conidia and integrated conidiogenous cells. Therefore, we exclude Helicosporium gracile from Helicosporium. Besides, Tsui et al. (2006) provided ITS and LSU sequence data for their new record of Helicosporium gracile (CBS 284.54), but they did not describe its morphology. Our phylogenetic analyses show that Helicosporium gracile (CBS 284.54) shares a sister relationship to Helicangiospora lignicola, which also indicates that this taxon does not belong to Helicosporium. However, we did not synonymize this taxon because its morphology in previous studies are inconsistent and there is a lack of DNA sequence data. Therefore, we renamed the strain CBS 284.54 as Tubeufiaceae sp. to show that further studies are needed to resolve its identification problems.


Helicosporium hiospiroides B.S. Reddy, D. Rao & G.V. Rao, Curr. Sci. 39(9): 215 (1970)

Index Fungorum: IF 315042

Notes: Helicosporium hiospiroides was introduced by Reddy et al. (1970). Goos (1989) regarded this species resembled Helicosporium virescens apart from its branched conidiophores which can be easily recognized. We exclude this species from Helicosporium because its conidiophores and conidia morphology does not tally with other Helicosporium species accepted based on phylogeny.


Helicosporium raghuveeri V.G. Rao & Varghese [as ‘raghuveerii’], Int. J. Mycol. Lichenol. 3(2-3): 297 (1988)

Index Fungorum: IF 125440

Notes: Rao and Varghese (1988) reported that the conidial diameter of Helicosporium raghuveeri (60–85 μm diam.) was larger than other Helicosporium species. However, this characteristics do not tally with the generic description of Helicosporium, and thus, we exclude this species from Helicosporium.


Helicotruncatum Y.Z. Lu, J.C. Kang & K.D. Hyde, gen. nov

Index Fungorum: IF 554859; Facesoffungi number: FoF 04730

Etymology: “Helicotruncatum” referring to the unique truncate basal cells of helicoid conidia and conidiogenous cells.

Saprobic on decaying wood. Sexual morph: undetermined. Asexual morph: hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, velvety black; on corn meal agar, slow-growing, thin, effused brownish grey. Mycelium composed of brownish grey hyphae. Conidiophores macronematous, mononematous, cylindrical, erect, stout, unbranched, septate, brownish grey, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, sympodial, cylindrical, terminal, or lateral due to proliferation of the conidiophore, truncate at apex after conidial secession, with broad, flat point of conidial attachment, smooth-walled. Conidia solitary, acropleurogenous, helicoid, the basal cell truncate with thickened lateral walls, coiled 1¾–2 times, not becoming loose in water, 10–16-septate, dilute fuliginous, smooth-walled.

Type species: Helicotruncatum palmigenum (Penz. & Sacc.) Y.Z. Lu & K.D. Hyde

Notes: The new genus Helicotruncatum is morphologically unique as compared to other helicosporous hyphomycetes in that the lateral cell wall of the conidiophore and the basal cell of the conidium are distinctively thickened. Phylogenetically, Helicotruncatum shares a close relationship to Helicomyces and Tubeufia, but the phylogenetic result shows that it is an independent lineage (Clade 3) (Fig. 2).


Helicotruncatum palmigenum (Penz. & Sacc.) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium intermedium var. palmigenum Penz. & Sacc., Malpighia 15(7–9): 249 (1902) [1901]

≡ Helicoma palmigenum (Penz. & Sacc.) Linder, Ann. Mo. bot. Gdn 16: 306 (1929)

= Helicoma westonii Linder [as ‘westoni’], Ann. Mo. bot. Gdn 18: 12 (1931)

Index Fungorum: IF 554860; Facesoffungi number: FoF 04800

Type: Goos (1986) pointed out that no type specimens are available.

Possible distribution: Australia, Brazil, China (Taiwan), Indonesia, Japan, Mexico, New Guinea, Seychelles, Trinidad, USA (Hawaii).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Linder (1929, as Helicoma westonii) and Matsushima (1971, as Helicoma palmigenum) and Goos (1986, as Helicoma palmigenum).

Notes: This taxon was introduced as Helicoma palmigenum by Linder (1929) based on its greater dimensions and fewer septa of the conidia, which were distinct from H. intermedium. Matsushima (1971) reported a new record of this species. Goos (1986) reexamined Matsushima’s specimen and the type of H. westonii and synonymized Helicoma westonii under H. palmigenum based on their identical morphology. Tsui and Berbee (2006) provided the ITS and LSU sequence data (NBRC 32663) for this species. However, our phylogenetic result showed that H. palmigenum shares a close relationship to Pseudohelicomyces and Tubeufia but far away from Helicoma (Fig. 2) which indicates that this taxon does not belong to Helicoma. After comparing its morphology to other helicosporous species including our new isolates in this study, we consider that this taxon is distinct from other described helicosporous genera by its unique conidia and conidiogenous cells. Therefore, we introduced it as Helicotruncatum palmigenum.


Neoacanthostigma Boonmee, Bhat & K.D. Hyde, Fungal Diversity 68(1): 278 (2014)

Index Fungorum: IF 550576

Known distribution for type species: Thailand.

Saprobic on decaying wood. Sexual morph Ascomata superficial, solitary, scattered, globose to subglobose, reddish-brown to dark brown, to black, setose, coriaceous, with a central ostiole. Ostiole single, central. Setae covering the whole ascoma, tapering towards an acute tip, unbranched, dark brown to black, thick-walled. Peridium composed of several layers of brown cells of textura angularis. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindric-clavate, with a short rounded pedicel, with thick and rounded apex, ocular chamber not observed. Ascospores fasciculate, cylindrical, narrowly fusiform, tapering towards narrow, subacute ends, trans-septate, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Conidiophores lacking. Conidiogenous cells monoblastic, holoblastic, integrated, sympodial, arising as lateral branches from creeping hyphae, cylindrical, truncate at apex, up to 5 μm long, hyaline, smooth-walled. Conidia solitary, acrogenous, helicoid, rounded at tip, with conidial filament loosely coiled, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Type species: Neoacanthostigma fusiforme Boonmee, Bhat & K.D. Hyde, Fungal Diversity 68(1): 279 (2014)

Notes: The genus Neoacanthostigma was introduced by Boonmee et al. (2014) based on the type species N. fusiforme. Acanthostigma filiforme and A. septoconstrictum were synonymized under Neoacanthostigma based on phylogenetic analyses (Boonmee et al. 2014). Hyde et al. (2016a) reported a new record of N. septoconstrictum, which was reappraised by Tanney and Miller (2017) as N. thailandicum. Besides, Tanney and Miller (2017) synonymized N. septoconstrictum under Berkleasmium concinnum, and pointed out that the transfer of Acanthostigma filiforme to Neoacanthostigma appeared unwarranted given by its phylogenetic distance from N. fusiforme. Lu et al. (2017c) introduced four new Neoacanthostigma species, viz. N. aquaticum, N. brunneisporum, N. guangxiense and N. latisporum. In this study, we synonymized N. aquaticum, N. brunneisporum, N. guangxiense, N. latisporum and N. thailandicum under the genus Berkleasmium, and N. filiforme under the genus Acanthotubeufia based on morphological and phylogenetic evidence. The type species N. fusiforme is the only existing species in Neoacanthostigma (Clade 36) (Fig. 2).


Neochlamydotubeufia Y.Z. Lu, Boonmee & K.D. Hyde, gen. nov

Index Fungorum: IF 554861; Facesoffungi number: FoF 04731

Saprobic on decaying wood. Sexual morph Ascomata superficial, solitary or scattered, globose to subglobose, dark brown to black, setose, coriaceous, with a central ostiole. Ostiole single, central. Setae covering the whole ascoma, dark brown to black, taper to an acute apex, unbranched, thick-walled. Peridium composed of several layers of cells of textura angularis. Hamathecium branched, hyaline pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, cylindrical to clavate, saccate, apically rounded, short pedicellate. Ascospores 2–3-seriate, fusiform, straight to slightly curved, tapering toward the ends, guttulate, multi-septate, not constricted at the septa, hyaline to pale brown. Asexual morph Hyphomycetous, chlamydosporous. Chlamydospores holoblastic, broadly oval to ellipsoid, dictyoseptate, pale brown when immature, darkened to black when matured, with terminal cells round and pale brown.

Type species: Neochlamydotubeufia fusiformis Y.Z. Lu, Boonmee & K.D. Hyde

Notes: The genus Neochlamydotubeufia shares similar sexual and asexual morphs to Chlamydotubeufia and Dictyospora. However, our phylogenetic result shows that Neochlamydotubeufia forms a distinct clade (Clade 14) and distant from Chlamydotubeufia and Dictyospora, and supports Neochlamydotubeufia as a distinct genus (Fig. 2). Despite its morphological resemblance to Chlamydotubeufia and Dictyospora, we introduced Neochlamydotubeufia gen. nov. in this study.


Neochlamydotubeufia fusiformis Y.Z. Lu, Boonmee & K.D. Hyde, sp. nov.

Index Fungorum number: IF 554862; Facesoffungi number: FoF 04732; Figs. 35 and 36

Fig. 35
figure 35

Neochlamydotubeufia fusiformis (MFLU 17–1164, holotype). a, b Superficial ascomata on substrate. Note ascomata surrounded by black setae. c Ascoma. d Peridium. e Seta. f–h Asci. i–p Ascospores. q Germinating ascospore. r, s Colony on MEA from above and below. Scale bars: a, b = 200 µm, c = 50 µm, d–q = 20 µm

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Fig. 36
figure 36

Asexual morph of Neochlamydotubeufia fusiformis (MFLU 17–1163, paratype). a Chlamydospores on natural substrata. b Conidiogenous cell with attached conidium. c–f, i–p Chlamydospores. g Germinating chlamydospore. h Mycelium with chlamydospores. q, r Colony on MEA from above and below. Notes h–p from its living cultures. Scale bars: a = 200 µm, b–p = 50 µm

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Holotype: MFLU 17–1164

Etymology: “fusiformis” referring to fusiform ascospores of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Ascomata 140–180 high × 140–170 μm diameter (\( \bar{x} \) = 155 × 150 μm, n = 10), superficial, solitary or scattered, globose to subglobose, black, setose, coriaceous, with a central ostiole. Ostiole single, central. Setae 50–80 × 3–5 μm, covering the whole ascoma, dark brown to black, taper to an acute apex, unbranched, thick-walled. Peridium 15–25 μm thick, composed of several layers of cells of textura angularis. Hamathecium 1–2 μm wide, branched, hyaline pseudoparaphyses. Asci 80–100 × 15–18 μm (\( \bar{x} \) = 90 × 16 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical to clavate, saccate, apically rounded, short pedicellate. Ascospores 35–40 × 5–6 μm (\( \bar{x} \) = 38 × 5.5 μm, n = 50), 2–3-seriate, fusiform, slightly curved, tapering toward the ends, enlarged at the 3rd cell, guttulate, 5–6-septate, not constricted at septa, hyaline to pale brown. Asexual morph Hyphomycetous, chlamydosporous. Chlamydospores 60–100 μm long, 40–60 μm diam. (\( \bar{x} \) = 67 × 35 μm, n = 20), holoblastic, sometimes intercalary, broadly oval to ellipsoid, dictyoseptate, pale brown when immature, darkened to black when matured, with terminal cells round and subhyaline.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing slowly on malt extract agar (MEA), circular, with flat surface, veined and without wrinkle, edge undulate, reaching 21 mm in 4 weeks at 28 °C, brown to dark brown in MEA media. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown.

Material examined: THAILAND, Uttaradit, Laplae, Mae Phun, Ban Ton Klua, on decaying wood in a freshwater stream, 24 October 2015, Saranyaphat Boonmee, UTD20 (MFLU 17–1164, holotype), ex-type living cultures, MFLUCC 16–0016, TBRC; Ibid., UTD15–3 (MFLU 17–1163, paratype), living culture, MFLUCC 16–0214.

Notes: Morphologically, Neochlamydotubeufia fusiformis resembles N. khunkornensis in ascomata and asci as well as ascospores, but can be recognized by its smaller ascomata (140–180 × 140–170 μm vs. 180–250 × 200–250 μm) (Boonmee et al. 2011, as Chlamydotubeufia khunkornensis) and ascospores enlarged at the 3rd cell while N. khunkornensis lacks this characteristic. Phylogenetically, our two new isolates formed a clade which shares a sister relationship to N. khunkornensis with high bootstrap support (Fig. 2) and supports them as distinct species. The asexual morph of N. fusiformis was found on natural decaying woody substrate, and we linked its asexual-sexual morphs based on their identical molecular data.

New combination of Neochlamydotubeufia

Neochlamydotubeufia khunkornensis (Boonmee & K.D. Hyde) Y.Z. Lu, comb. nov.

≡ Chlamydotubeufia khunkornensis Boonmee & K.D. Hyde, Fungal Diversity 51(1): 80 (2011)

Index Fungorum: IF 554863; Facesoffungi number: FoF 04733; Figs. 37 and 38

Fig. 37
figure 37

The asexual morph of Neochlamydotubeufia khunkornensis from natural decaying wood substrata. a Chlamydospores on natural substrata. b, c Conidiogenous cells with attached conidia. d–o Chlamydospores. Scale bars: a = 200 µm, b–o = 20 µm. Notes a–g MFLU 17–1167, h–k MFLU 17–1170, l–o MFLU 17–1181

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Fig. 38
figure 38

The asexual morph of Neochlamydotubeufia khunkornensis from cultures. a Germinating chlamydospore. b, c Colony on MEA from above and below. d Conidiogenous cells with attached conidia. e–o Conidiogenous cells with attached immature chlamydospores. p Matured chlamydospore. Scale bars: a, d = 50 µm, e–p = 20 µm

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Known distribution: Thailand

Habitat: Aquatic, Terrestrial.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph For a complete description of sexual morph of Neochlamydotubeufia khunkornensis see Boonmee et al. (2011, as Chlamydotubeufia khunkornensis). Asexual morph Hyphomycetous, chlamydosporous. Chlamydospores 50–135 μm long, 30–80 μm wide (\( \bar{x} \) = 85 × 55 μm, n = 50), holoblastic, sometimes intercalary, broadly oval to ellipsoid, dictyoseptate, pale brown when immature, darkened to black when matured, with terminal cells round and pale brown.

Culture characteristics: Conidia germinating on water agar and producing germ tubes within 36 h. Colonies growing slowly on malt extract agar (MEA), circular, with flat surface, veined and without wrinkle, edge entire, reaching 21 mm in 6 weeks at 28 °C, brown to dark brown in MEA media. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, becoming dark brown due to the development of chlamydospores (Fig. 38).

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 28 November 2015, Saranyaphat Boonmee and Yong-Zhong Lu, TUB05–1 (MFLU 17–1167 = HKAS 100723), living culture, MFLUCC 16–0025; Ibid., TUB03–4 (MFLU 17–1170), living culture, MFLUCC 16–1129; THAILAND, Krabi, Muang, Khao Khram, Ban Nong Jig, Tha Pom Klong Song Nam, on submerged decaying wood in freshwater stream, 16 December 2015, Saranyaphat Boonmee, TP01–5 (MFLU 17–1181), living culture, MFLUCC 16–1126.

Notes: Morphologically, our new collections found from decaying wood substrate have typical chlamydospores, which are similar to Chlamydotubeufia huaikangplaensis and Dictyospora thailandica (Brahamanage et al. 2017; Hyde et al. 2017). Phylogenetically, these three newly obtained isolates form a monotypic clade with two known Chlamydotubeufia khunkornensis isolates and can be recognized as one species (Fig. 2). Furthermore, our phylogenetic result shows that this taxon shares a sister relationship to Neochlamydotubeufia fusiformis but distantly related to Chlamydotubeufia and Dictyospora members, therefore, we synonymize it as Neochlamydotubeufia khunkornensis.


Neohelicoma Y.Z. Lu, Boonmee & K.D. Hyde, gen. nov.

Index Fungorum: IF 554864; Facesoffungi number: FoF 04734

Etymology: “Neohelicoma” referring to the morphology of this genus similar to the sexual morph of Helicoma.

Saprobic on decaying wood. Sexual morph Ascomata superficial, solitary, scattered, globose to subglobose, seated on a subiculum, yellowish to brownish, brown when dry, with a central ostiole. Ostiole single, central. Peridium composed of cells of textura angularis, with inner cells pale brown and outer cells reddish-brown to brown. Hamathecium comprising numerous, filiform, septate, branched, hyaline pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores 2–3-seriate, cylindric to fusiform, tapering towards rounded ends, straight to slightly curved, guttulate, multi-septate, slightly constricted at septa, hyaline when young, pale brown when matured, smooth-walled. Asexual morph Undetermined.

Type species: Neohelicoma fagacearum (Boonmee & K.D. Hyde) Y.Z. Lu

Notes: Our phylogenetic analyses show that the isolate MFLUCC 11–0379 shares a close relationship to Helicoarctatus aquaticus MFLUCC 17–1996 (Figs. 2, 15). However, we could not compare their morphology because one is sexual morph and another is asexual morph, but our phylogenetic result shows that they are different genera and therefore, Neohelicoma gen. nov. is introduced in this study.

New combination of Neohelicoma

Neohelicoma fagacearum (Boonmee & K.D. Hyde) Y.Z. Lu, comb. nov.

≡ Helicoma fagacearum Boonmee & K.D. Hyde, Fungal Diversity 68: 271 (2014)

Index Fungorum: IF 554865; Facesoffungi number: FoF 04801

Type: THAILAND, Chiang Rai, Muang, Doi Pui, on dead wood of Fagaceae, 10 May 2011, Saranyaphat Boonmee, MFLU 11–0138 (holotype), PDD 104456 (isotype); ex-type living cultures, MFLUCC 11–0379 = BCC 52030 = ICMP 20071.

Known distribution: Thailand.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Boonmee et al. (2014, as Helicoma fagacearum).

Notes: This taxon was introduced as Helicoma fagacearum by Boonmee et al. (2014) based on phylogenetic evidence. The relationships of this species are still uncertain and even in this study we note close affinities to Helicoarctatus aquaticus, Dematiotubeufia chiangraiensis and Kamalomyces but without bootstrap support (Fig. 15). In addition, our phylogenetic result shows that Helicoma fagacearum is phylogenetically apart from Helicoma species and therefore, we synonymize it as Neohelicoma fagacearum.


Neohelicomyces Z.L. Luo, Bhat & K.D. Hyde, Cryptog. Mycol. 38(1): 39 (2017)

Index Fungorum: IF 818820

Known distribution for type species: China (Yunnan)

Saprobic on submerged decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, sparsely branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, erect, septate, sparsely branched, arising directly on substrate, glistening, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, cylindric, with lateral minute denticles, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, with conidial filament tightly coiled, becoming loose in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Type species: Neohelicomyces aquaticus Z.L. Luo, Bhat & K.D. Hyde, Cryptog. Mycol. 38(1): 40 (2017)

Notes: The genus Neohelicomyces was introduced by Luo et al. (2017). In this study, we introduced a new species, Neohelicomyces hyalosporus, and synonymized Helicosporium pallidum under Neohelicomyces based on phylogenetic analyses and morphology. Moreover, Tubeufia helicomyces (MUCL 15702) grouped within Neohelicomyces but there is no morphological data from the authors who deposited the DNA sequence data (Tsui et al. 2006; Tsui and Berbee 2006). Hence, we do not change its taxonomic status and new collections and molecular data are needed to clarify its relationships.


Neohelicomyces hyalosporus Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554866; Facesoffungi number: FoF 04735; Fig. 39

Fig. 39
figure 39

Neohelicomyces hyalosporus (HKAS 97441, holotype). a Colony on decaying wood. b, c Conidiophores with conidia. d–f Conidiogenous cells. g–i Conidia. j, k Colonies on PDA from above and below. Scale bars: b, c = 50 µm, d–f = 20 µm, g–i = 10 µm

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Holotype: HKAS 97441

Etymology: “hyalosporus” referring to hyaline helicospores of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, unbranched, septate, 210–290 μm long, 3–4 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, with denticles, 9–20 μm long, 3–4 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 14–20 μm diam. and conidial filament 1.5–2.5 μm wide (\( \bar{x} \) = 17 × 2 μm, n = 50), 120–140 μm long, tightly coiled 2½–3¾ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with umbonate surface, veined and wrinkle, edge entire, reaching 12 mm in 2 weeks at 28 °C, brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 14 May 2016, Yong-Zhong Lu, PF11–1 (HKAS 97441, holotype; GZAAS 16–0098, isotype), ex-type living culture, GZCC 16–0086.

Notes: Neohelicomyces hyalosporus morphologically resembles Neohelicomyces pallidus (Linder 1929; Goos1989; Zhao et al. 2007, as Helicosporium pallidum) in conidiophores and conidiogenous cells as well as conidia. We could not distinguish them based on morphological characters. However, phylogenetically, N. hyalosporus is nested in between N. grandisporus and N. pallidus but without bootstrap support (Fig. 2). Following the recommendation of Jeewon and Hyde (2016) for delimitation of new species, we looked into pair wise dissimilarities of DNA sequences and noted that there are 37 and 4 noticeable nucleotide differences in ITS and LSU sequence data respectively between our new isolate GZCC 16–0086 and N. pallidus (CBS 962.69), which indicates that they are distinct species. Therefore, Neohelicomyces hyalosporus sp. nov. is introduced here.

New combination of Neohelicomyces


Neohelicomyces pallidus (Cesati) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium pallidum Ces., Bot. Ztg. 13: 598 (1855)

Index Fungorum: IF 554867; Facesoffungi number: FoF 04802

Type: EUROPE, Cesati Herb. No. 62.

Possible distribution: China (Guangdong, Hebei, Liaoning, Tibet), Czech, Italy, Japan, USA (Massachusetts).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Linder (1929, as Helicosporium pallidum), Goos (1989, as Helicosporium pallidum) and Zhao et al. (2007, as Helicosporium pallidum).

Notes: This taxon was introduced as Helicosporium pallidum by previous studies (Linder 1929; Goos 1989; Tsui et al. 2006; Zhao et al. 2007). Tsui et al. (2006) provided the ITS and LSU sequence data (CBS 962.69 and UAMH 10535). However, our phylogenetic analyses showed that both CBS 962.69 and UAMH 10535 grouped within Neohelicomyces (Fig. 2). Besides, its morphology also fits well within Neohelicomyces and distinct to Helicosporium species, thus, we synonymize this taxon under Neohelicomyces pallidus. Furthermore, we note that Neohelicomyces pallidus CBS 962.69 and UAMH 10535 are clearly phylogenetically apart, and there are 4 bp and 31 bp noticeable nucleotide differences in LSU and ITS sequence data respectively between them, which indicate that they should be treated as distinct species. However, we are not able to differentiate them as Tsui et al. (2006) only provided two illustrations for Helicosporium pallidum but did not describe the morphology from which specimen. Therefore, we retained both CBS 962.69 and UAMH 10535 as Neohelicomyces pallidus until new morphological and molecular evidence are provided. In addition, we also note that there are two isolates, Helicosporium phragmitis (CBS 271.52) (Tsui et al. 2006; NCBI data base as Tubeufia helicomyces CBS 271.52) and Tubeufia paludosa (CBS 245.49) (Ruibal et al. 2009), clustered together with Neohelicomyces pallidus (CBS 962.69). We also compared their nucleotides and found no difference between them, which proved that they are the same species. Therefore, we renamed CBS 271.52 and CBS 245.49 as Neohelicomyces pallidus.

Other accepted Neohelicomyces species

Neohelicomyces aquaticus Z.L. Luo, Bhat & K.D. Hyde, Cryptog. Mycol. 38(1): 40 (2017)

Index Fungorum: IF 818822

Known distribution: China (Yunnan).

Habitat: Aquatic.

Notes: This taxon was introduced by Luo et al. (2017) based on phylogeny and morphological evidence.


Neohelicomyces grandisporus Z.L. Luo, Boonmee & K.D. Hyde, Cryptog. Mycol. 38(1): 44 (2017)

Index Fungorum: IF 818824

Known distribution: China (Yunnan).

Habitat: Aquatic.

Notes: This taxon was introduced by Luo et al. (2017) based on phylogeny and morphological evidence.


Neohelicomyces submersus Z.L. Luo, Hong Y. Su & K.D. Hyde, Cryptog. Mycol. 38(1): 40 (2017)

Index Fungorum: IF 818823

Known distribution: China (Yunnan).

Habitat: Aquatic.

Notes: This taxon was introduced by Luo et al. (2017) based on phylogeny and morphological evidence.


Neohelicosporium Y.Z. Lu, J.C. Kang & K.D. Hyde, Mycol. Progr. 17 (5): 637 (2017)

Index Fungorum: IF 822045

Saprobic on decaying woody substrate. Sexual morph Ascomata superficial, seated on a subiculum, solitary, scattered, subglobose, ellipsoidal-ovate, coriaceous, pale brown to dark brown, with a central ostiole, without setae. Peridium composed of cells of textura angularis, with inner cells pale brown and outer cells brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores 2–3-seriate, fusiform, tapering towards rounded ends, straight or slightly curved, multi-septate, guttulate, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to light pink. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous or macronematous, mononematous, erect, flexuous, cylindrical, branched or unbranched, septate, arising from creep hyphae, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, with denticles, hyaline to brown, smooth-walled. Conidia solitary, acrogenous and/or acropleurogenous, helicoid, rounded at tip, multi-septate, guttulate, hyaline to pale brown, smooth-walled.

Type species: Neohelicosporium parvisporum Y.Z. Lu, J.C. Kang & K.D. Hyde, Mycol. Progr. 17 (5): 637 (2017)

Notes: Neohelicosporium was established by Lu et al. (2018) based on phylogeny and morphological evidence. Neohelicosporium differs from Helicosporium in having acrogenous and/or acropleurogenous conidia developing from an integrated, sympodial conidiogenous cells while Helicosporium species have pleurogenous conidia and discrete, determinate conidiogenous cells. Eight previously described Helicosporium species were synonymized under Neohelicosporium based on morphology, viz. Helicosporium abuense, H. griseum, H. lumbricoides, H. taiwanense, H. nizamabadense, H. sympodiophorum, H. myrtacearum, H. vesiculiferum. Besides, Helicoma morganii, H. violaceum and Tubeufia aurantiella were synonymized under Neohelicosporium based on morphological and phylogenetic evidence. Helicosporium panacheum is synonymized under Neohelicosporium guangxiense based on phylogenetic analyses. Two strains, Helicomyces macrofilamentosus (HKUCC 10235) and Helicomyces torquatus (CBS 189.95), were renamed as Neohelicosporium sp. We considered that these are misidentifications as phylogenetically they belong to Neohelicosporium but their morphologies do not fit within the generic concept of Neohelicosporium at all. New collections and molecular data are needed to solve the taxonomic problems of these two taxa.


Neohelicosporium acrogenisporum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554868; Facesoffungi number: FoF 04736; Fig. 40

Fig. 40
figure 40

Neohelicosporium acrogenisporum (MFLU 17–1103, holotype). a Colony on decaying wood. b, c Conidiophores. d–e Conidiogenous cells. f Conidiogenous cell with attached conidium. g–l Conidia. m, n Colonies on MEA from above and below. Scale bars: a = 200 µm, b, c, f–l = 50 µm, d, e = 10 µm

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Holotype: MFLU 17–1103

Etymology: “acrogenisporum” referring to acrogenous helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, mostly unbranched, occasionally branched, septate, 45–150 μm long, 6–7 μm wide, brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, with denticles, 12–15 μm long, 4–6 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acrogenous, helicoid, rounded at tip, 45–60 μm diam. and conidial filament 4.5–7.5 μm wide (\( \bar{x} \) = 52 × 6 μm, n = 20), 345–470 μm long, coiled 2½–3½ times, becoming loosely coiled in water, indistinctly multi-septate, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, circular, with flat surface, edge filiform, reaching 15 mm in 4 weeks at 28 °C, brown to dark brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR20 (MFLU 17–1103, holotype; HKAS 100773, isotype), ex-type living cultures, MFLUCC 17–2019, TBRC 8908.

Notes: Morphologically, Neohelicosporium acrogenisporum is distinct from other Neohelicosporium species by its larger acrogenous conidia and longer conidial filaments. Phylogenetically, N. acrogenisporum shares a sister relationship to N. ellipsoideum with good bootstrap support (Fig. 2) and support that they are distinct species.


Neohelicosporium astrictum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554869; Facesoffungi number: FoF 04737; Fig. 41

Fig. 41
figure 41

Neohelicosporium astrictum (MFLU 17–1144, holotype). a Colony on decaying wood. b, c Conidiophores. d–f Conidiogenous cells. g–k Conidia. l, m Colonies on PDA from above and below. n Umbonate colony surface on PDA from above. Scale bars: a, b = 100 µm, c–k = 10 µm

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Holotype: MFLU 17–1144

Etymology: “astrictum” referring to tightly helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores micronematous, mononematous, cylindrical, branched or unbranched, septate, 50–280 μm long, 3–4.5 μm wide, brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, with denticles, 11–20 μm long, 3.5–4.5 μm wide, brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 17–21 μm diam. and conidial filament 2–3.5 μm wide (\( \bar{x} \) = 19 × 2.8 μm, n = 50), 100–115 μm long, tightly coiled 2¼–2¾ times, not becoming loose in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with umbonate surface, slightly wrinkle, edge entire, reaching 19 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW14 (MFLU 17–1144, holotype; HKAS 100815, isotype), ex-type living cultures, MFLUCC 17–2004, TBRC 8909.

Notes: Presently, there are three Neohelicosporium species, N. astrictum sp. nov., N. aquaticum and N. ellipsoideum sp. nov., in which the conidia do not become loosely coiled or uncoiled in water. Neohelicosporium astrictum is distinct from N. aquaticum by its smaller conidia diameter (17–21 μm vs. 27–32 μm) as well as the thinner and shorter conidial filaments (2–3.5 × 100–115 μm vs. 4–5.5 × 150–185 μm). Neohelicosporium astrictum is distinct from N. ellipsoideum by its thinner conidial filaments (2–3.5 μm vs. 5.5–7 μm) and thinner conidiophores (3–4.5 μm vs. 5–6 μm). Phylogenetically, N. astrictum constitutes an independent lineage with weak support and sister to N. fusisporum and N. parvisporum isolates within the genus Neohelicosporium (Fig. 2).


Neohelicosporium ellipsoideum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554870; Facesoffungi number: FoF 04738; Figs. 42 and 43

Fig. 42
figure 42

The sexual morph of Neohelicosporium ellipsoideum (MFLU 17–1180, holotype). a Superficial ascomata on substrate. b Ascoma. c Peridium. d Ostiole. e Subiculum. f Hamathecium. g–k Asci. l–r Ascospores. Scale bars: a = 200 µm, b = 100 µm, c, e, f, l–r = 20 µm, d, g–k = 50 µm

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Fig. 43
figure 43

The asexual morph of Neohelicosporium ellipsoideum (from asexual morph’s cultures). a, b Colonies on MEA from above and below. c–f Conidiogenous cell with attached conidia. g–i Conidiogenous cells. j–l Conidia. Scale bars: c–g, j–l = 20 µm, h, i = 10 µm

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Holotype: MFLU 17–1180

Etymology: “ellipsoideum” referring to the ovoid ascomata of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Ascomata 200–320 μm high × 150–290 μm diam., superficial, seated on a subiculum, solitary, scattered, ellipsoidal to subglobose, upper part pale brown, under part dark brown, coriaceous, with a central ostiole. Ostiole single, central. Peridium 25–35 μm wide, composed of cells of textura angularis, brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 110–140 × 15–18 μm (\( \bar{x} \) = 125 × 16 μm, n = 20), 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores 50–65 × 5–7 μm (\( \bar{x} \) = 58 × 6 μm, n = 20), 2–3-seriate, fusiform, tapering towards rounded ends, slightly curved, guttulate, 7–9-septate, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Conidiophores macronematous, mononematous, cylindrical, branched or unbranched, septate, 50–230 μm long, 5–6 μm wide, brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, with denticles, 15–25 μm long, 5–6 μm wide, pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 20–30 μm diam. and conidial filament 5.5–7 μm wide in the broadest part (\( \bar{x} \) = 25 × 6 μm, n = 20), tapering to 3–4 μm wide at apex and base, 85–115 μm long, tightly coiled 2–2½ times, not becoming loose in water, 14–15-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing on MEA, circular, with slightly umbonate surface, edge entire, reaching 11 mm in 2 weeks at 28 °C, brown to dark brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Krabi, Plai Praya, Khao To, Ban Bang Thao Mae, on decaying wood in flowing freshwater stream, 17 December 2015, Saranyaphat Boonmee, BTM01–4 (MFLU 17–1180, holotype; HKAS 100757, isotype), living culture, MFLUCC 16–0229.

Notes: Neohelicosporium ellipsoideum is the second sexual morph in the genus Neohelicosporium. Neohelicosporium ellipsoideum is distinct from N. fusisporum by its shorter ascomata (200–320 μm vs. 340–400 μm), wider asci (15–18 μm vs. 9–12 μm) and wider ascospores (5–7 μm vs. 1.6–4.6 μm). The asexual morph of N. ellipsoideum was found from the culture obtained from sexual morph by single spore isolation. The most similar asexual morph species to this taxon in the genus Neohelicosporium is N. aquaticum. Both of them have wide conidial filament and conidia do not become loose in water. However, N. ellipsoideum differs from N. aquaticum by its wider (5.5–7 μm vs. 4–5.5 μm) and shorter (85–115 μm vs. 150–185 μm) conidial filaments. Phylogenetically, Neohelicosporium ellipsoideum is sister to N. acrogenisporum with good bootstrap support (Fig. 2). We compared their nucleotides and noted that there are 9, 2, 23 and 16 noticeable nucleotide differences in ITS, LSU, RPB2 and TEF1α sequence data respectively between N. ellipsoideum (MFLUCC 16–0229) and N. acrogenisporum (MFLUCC 17–2019), which indicates that they are distinct species. Therefore, based on both morphological and phylogenetic evidence, N. ellipsoideum is identified as a new species of Neohelicosporium.


Neohelicosporium guangxiense Y.Z. Lu, J.C. Kang & K.D. Hyde, Mycol. Progr. 17 (5): 639 (2017)

= Helicosporium panacheum R.T. Moore, Mycologia 46(1): 92 (1954)

Index Fungorum: IF 822058; Facesoffungi number: FoF 03573

Possible distribution: Canada (British Columbia), China▲ (Guangdong, Guangxi), Japan, USA (Hawaii, Iowa).

Habitat: Aquatic, Terrestrial.

Description: For a complete description of this taxon see Lu et al. (2018).

Material examined: CHINA, Guangxi Province, Hechi City, on submerged decaying wood in a freshwater stream, 18 May 2016, Yong-Zhong Lu, XSL02 (GZAAS 16–0080), living culture, GZCC 16–0068; CHINA, Guangxi Province, Hechi City, Mulun National Nature Reserve, on decaying wood in terrestrial habitat on a mountain, 19 May 2016, Yong-Zhong Lu, ML04–1 (HKAS 97435 = GZAAS 16–0074), living culture, MFLUCC 17–0054 = GZCC 16–0062.

Notes: Two new isolates, one collected from terrestrial habitat and another one from aquatic habitat, were identified as Neohelicosporium guangxiense based on their identical morphologies and molecular data. It is the first record of N. guangxiense from terrestrial habitat.

In addition, Helicosporium panacheum was introduced by Moore (1954). Goos (1989) reexamined the type material and another specimen (specimen number, R. J. Bandoni 7367) and accepted Moore’s identification. Tsui et al. (2006) provided its ITS and LSU sequence data but there seems to be some confusion in the strain H. panacheum being cited in their discussion and the H. panachaeum CBS 257.59 mentioned in the table displaying the list of taxa used. Zhao et al. (2007) reported a new record of H. panacheum from China. However, our phylogenetic analyses show that this taxaon grouped within Neohelicosporium and nested with Neohelicosporium guangxiense isolates, which indicates that this taxon should be a Neohelicosporium species. We also compared their DNA sequence data and there is only one base pair difference in ITS and no difference in LSU between H. panachaeum CBS 257.59 and the ex-type strain of N. guangxiense (MFLUCC 17–1522). Therefore, despite having slightly different morphs pertaining to conidiophores and conidia, we identified them as the same species and H. panacheum is synonymized under N. guangxiense.


Neohelicosporium hyalosporum Y.Z. Lu, J.C. Kang & K.D. Hyde, Mycol. Progr. 17 (5): 641 (2017)

Index Fungorum: IF 822059; Facesoffungi number: FoF 03574

Known distribution: China (Guangxi).

Description: For a complete description of this taxon see Lu et al. (2018).

Habitat: Aquatic, Terrestrial.

Material examined: CHINA, Guangxi Province, Hechi City, Mulun National Nature Reserve, on decaying wood in terrestrial habitat on a mountain, 19 May 2016, Yong-Zhong Lu, ML05–1 (HKAS 97436 = GZAAS 16–0075), living culture, GZCC 16–0063.

Notes: One new specimen collected from terrestrial habitat was identified as Neohelicosporium hyalosporum based on their identical morphology and molecular data. It is the first record of N. hyalosporum from terrestrial habitat.


Neohelicosporium irregulare Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554871; Facesoffungi number: FoF 04739; Figs. 44 and 45

Fig. 44
figure 44

Neohelicosporium irregulare (MFLU 17–1095, holotype). a Colony on decaying wood. b–e Conidiophores. f–j Conidiogenous cells. k–o Conidia. p, q Colonies on MEA from above and below. Scale bars: a = 200 µm, b–e = 50 µm, f, k–o = 20 µm, g–j = 10 µm

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Fig. 45
figure 45

Neohelicosporium irregulare (MFLU 17–1117, paratype). a Colony on decaying wood. b–e Conidiophores. f–l Conidia. m, n Colonies on MEA from above and below. Scale bars: a = 200 µm, b–l = 20 µm

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Holotype: MFLU 17–1095

Etymology: “irregulare” referring to irregular conidiophores of this fungus.

Known distribution: Thailand.

Habitat: Aquatic, Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, mostly unbranched, occasionally branched, septate, exist two kind of length, the longer one 90–265 μm long, 4–6 μm wide at bottom, tapering to 1–2 μm wide at apex, the shorter one 35–55 μm long, 4.5–7 μm wide, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, with denticles, some of them are arising laterally from the conidiophores as tiny bladder-like protrusions (Fig. 44f, h), 12–22 μm long, 3–5.5 μm wide, pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 25–40 μm diam. and conidial filament 3.5–4.5 μm wide (\( \bar{x} \) = 32 × 4 μm, n = 20), 150–270 μm long, coiled 1½–2 times (coiled 3–4 times in paratype MFLU 17–1117), becoming loosely coiled or uncoiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, irregular, with flat surface, edge undulate, reaching 19 mm in 4 weeks at 28 °C, brown to dark brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR12–2 (MFLU 17–1095, holotype; HKAS 100765, isotype), ex-type living cultures, MFLUCC 17–1796, TBRC 8906; THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on decaying wood in a mountain, 25 January 2017, Yong-Zhong Lu, MRC18 (MFLU 17–1117, paratype), living culture, MFLUCC 17–1808.

Notes: Two isolates of Neohelicosporium irregulare were collected from different habitats (the holotype MFLU 17–1095 was from aquatic habitat and the paratype MFLU 17–1117 was from terrestrial habitat). It is necessary to point out that their conidiophores are irregular, there are long and short conidiophores that coexist in both of them (Figs. 44, 45). The conidiogenous cells of MFLU 17–1095 are also irregular, most of them are denticulate protrusions but some are tiny bladder-like protrusions (Fig. 44f, h). The conidia of MFLU 17–1095 has only 1½–2 coils but MFLU 17–1117 are coiled 3–4 times and become loose in water. However, our multi-gene phylogenetic analyses show that these two isolates should be the same species given that they cluster together (Fig. 2). We also compared their nucleotides, and there are only 1, 1, 1, 3 base pairs differences in their ITS, LSU, RPB2 and TEF1α respectively, which also indicate that they are the same species. Therefore, despite having slightly different morphs pertaining to the number of coils, we identified them as the same species.


Neohelicosporium krabiense Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554872; Facesoffungi number: FoF 04740; Fig. 46

Fig. 46
figure 46

Neohelicosporium krabiense (HKAS 100725, holotype). a Colony on decaying wood. b Conidiophores with attached conidia. c, d Conidiophores. e, f Conidiogenous cells. g–k Conidia. l, m Colonies on PDA from above and below. Scale bars: a = 200 µm, b = 50 µm, c, d, g–k = 20 µm, e, f = 10 µm

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Holotype: HKAS 100725

Etymology: “krabiense” referring to collecting site.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, unbranched, septate, 45–140 μm long, 5–6.5 μm wide, brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, 12–18 μm long, 5–6 μm wide, brown, with hyaline denticles, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 30–40 μm diam. and conidial filament 3–4 μm wide (\( \bar{x} \) = 35 × 3.5 μm, n = 20), 230–320 μm long, tightly coiled 2½–3½ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, with umbonate surface, wrinkled, edge undulate, reaching 9 mm in 2 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Krabi, Muang, Nongtalay, Khao Hang Nak, on decaying wood in a freshwater stream, 16 December 2015, Saranyaphat Boonmee, HN05–3 (HKAS 100725, holotype), ex-type living culture, MFLUCC 16–0224.

Notes: Morphologically, Neohelicosporium krabiense is most similar to N. acrogenisporum in shape of conidia and conidiophores but can be distinguished by its smaller-sized conidia. Phylogenetically, N. krabiense shares a sister relationship to Neohelicosporium sp. (CBS 189.95) and Neohelicosporium sp. (HKUCC 10235) (Fig. 2). We could not compare their morphology because the later two lack morphological information, but phylogeny indicates that they are distinct species. Therefore, N. krabiense is identified as a new species in this study.


Neohelicosporium laxisporum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554873; Facesoffungi number: FoF 04741; Fig. 47

Fig. 47
figure 47

Neohelicosporium laxisporum (MFLU 17–1107, holotype). a Colony on decaying wood. b Conidiophores. c–g Conidiogenous cells. h–j Conidia. k Germinating conidium. l, m Colonies on MEA from above and below. Scale bars: a = 100 µm, b, h–k = 20 µm, c–g = 10 µm

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Holotype: MFLU 17–1107

Etymology: “laxisporum” referring to loosely helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, bulb at the apex, unbranched, septate, 20–160 μm long, 3.5–5 μm wide at bottom, 1.5–2.5 μm wide at apex, the lower part brown and the upper part hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, with denticles, 11–18 μm long, 3–4 μm wide, pale brown to brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 27–33 μm diam. and conidial filament 3–4 μm wide (\( \bar{x} \) = 27 × 3.5 μm, n = 20), 150–240 μm long, tightly coiled 2½–3½ times, becoming loosely coiled or uncoiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, irregular, with a slightly umbonate surface, a few wrinkled, edge undulate, reaching 20 mm in 4 weeks at 28 °C, brown to dark brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on dead bamboo in a mountain, 25 January 2017, Yong-Zhong Lu, MRC06 (MFLU 17–1107, holotype), ex-type living cultures, MFLUCC 17–2027, TBRC 8907.

Notes: Morphologically, Neohelicosporium laxisporum resembles N. irregulare in conidia but can be distinguished by conidiophores. The conidiophores of N. laxisporum expand to bulb-like at the apex but N. irregulare lacks this characteristic. Phylogenetically, N. laxisporum shares a close relationship to N. taiwanense and N. irregulare (Fig. 2). Following the recommendation of Jeewon and Hyde (2016) for delimitation of new species, we looked into pair wise dissimilarities of DNA sequences and noted that there are 8, 1, 12 and 14 noticeable nucleotide differences between N. laxisporum and N. irregulare in ITS, LSU, RPB2 and TEF1α sequence data respectively, which indicate that they are distinct species. There are 6 noticeable nucleotide differences between N. laxisporum and N. taiwanense in ITS, but we cannot compare other gene regions because only ITS data is available for N. taiwanense. However, N. laxisporum can be distinguished from N. taiwanense by its smaller conidia (27–33 × 3–4 μm vs. 37–48 × 4–5 μm) and shorter conidiophores (20–160 μm vs. 100–340 μm), besides, N. irregulare is not characterized by conidiophores expanding to bulb-like apex.


Neohelicosporium ovoideum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554874; Facesoffungi number: FoF 04742; Figs. 48 and 49

Fig. 48
figure 48

The sexual morph of Neohelicosporium ovoideum (GZAAS 16–0076, holotype). a Superficial ascomata on substrate. b Peridium. c–f Asci. g Hamathecium. h–l Ascospores. m, n Colonies on PDA from above and below. Scale bars: a = 200 µm, b–l = 20 µm

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Fig. 49
figure 49

The asexual morph of Neohelicosporium ovoideum (GZAAS 16–0078, paratype). a Colony on decaying wood. b, c Conidiophores with conidia. d Conidiophores. e, f Conidiogenous cells. g–j Conidia. Scale bars: b–d = 50 µm, e–j = 20 µm

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Holotype: GZAAS 16–0076

Etymology: “ovoideum” referring to the ovoid ascomata of this fungus.

Known distribution: China (Guangxi).

Habitat: Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Ascomata 180–250 μm high × 140–200 μm diam., superficial, seated on a subiculum, solitary, scattered, ovoid, coriaceous, with a central ostiole. Ostiole single, central. Peridium 20–30 μm wide, composed of cells of textura angularis, brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 90–130 × 10–14 μm (\( \bar{x} \) = 110 × 12 μm, n = 20), 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores 40–55 × 3–4 μm (\( \bar{x} \) = 47 × 3.3 μm, n = 50), 2–3-seriate, fusiform, tapering towards rounded ends, straight or slightly curved, guttulate, indistinctly multi-septate, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, hyaline to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores micronematous, mononematous, cylindrical, branched, septate, up to 420 μm long, 4–6 μm wide, brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal and intercalary, cylindrical, with denticles, 10–15 μm long, 4–6 μm wide, brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 25–35 μm diam. and conidial filament 3–4 μm wide (\( \bar{x} \) = 28 × 3.5 μm, n = 50), 180–230 μm long, tightly coiled 2–3 times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing on PDA, irregular, with flat surface, edge undulated, reaching 17 mm in 3 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Hechi City, Mulun National Nature Reserve, on decaying wood in terrestrial habitat on a mountain, 19 May 2016, Yong-Zhong Lu, ML06–1 (GZAAS 16–0076, holotype), ex-type living culture, GZCC 16–0064; Ibid., ML06–4 (GZAAS 16–0078, paratype), living culture, GZCC 16–0066.

Notes: The sexual morph of Neohelicosporium ovoideum resembles N. fusisporum in ascomata, asci and ascospores morphology, but can be recognized by its smaller ascomata (180–250 × 140–200 μm vs. 340–400 × 235–290 μm) and shorter asci (90–130 μm vs. 130–165 μm) (Jayasiri et al. 2017). Its asexual morph is identical to N. hyalosporum in conidiophores, conidiogenous cells and conidia (Lu et al. 2018). Phylogenetically, N. ovoideum shares a sister relationship to N. hyalosporum and phylogeny supports that they should be distinct species (Fig. 2). Furthermore, we also compared nucleotide among the 1045 nucleotides analyzed in the RPB2 sequences and found 30 noticeable differences between N. ovoideum and N. hyalosporum, which confirmed that they are distinct species. Therefore, we introduce it as a novel Neohelicosporium species.


Neohelicosporium parvisporum Y.Z. Lu, J.C. Kang & K.D. Hyde, Mycol. Progr. 17 (5): 637 (2017)

Index Fungorum: IF 822056; Facesoffungi number: FoF 03571

Known distribution: China (Guangxi), Thailand.

Habitat: Aquatic, Terrestrial.

Description: For a complete description of this taxon see Lu et al. (2018).

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, JHC05–3 (GZAAS 16–0107), living culture, MFLUCC 17–1521, GZCC 16–0095; THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR07 (MFLU 17–1090 = HKAS 100760), living culture, MFLUCC 17–1793; THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on decaying wood in a mountain, 25 January 2017, Yong-Zhong Lu, MRC11 (MFLU 17–1112 = HKAS 100785), living culture, MFLUCC 17–1804; Ibid., MRC 17 (MFLU 17–1116), living culture, MFLUCC 17–1807; THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW05 (MFLU 17–1135 = HKAS 100806), living culture, MFLUCC 17–1995; Ibid., on decaying wood in a mountain, 26 April 2017, Yong-Zhong Lu, TM04 (MFLU 17–1151 = HKAS 100822), living culture, MFLUCC 17–2010.

Notes: Neohelicosporium parvisporum was introduced by Lu et al. (2018) as the type species. In this paper, six newly obtained isolates were identified as N. parvisporum based on their identical morphology and molecular data. Besides, two of them were collected from aquatic habitat, and three from terrestrial habitat. It is the first record of N. parvisporum in Thailand and on terrestrial habitat.

New combinations of Neohelicosporium


Neohelicosporium abuense (Chouhan & Panwar) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium abuense Chouhan & Panwar, Indian Phytopath. 33(2): 289 (1980)

Index Fungorum: IF 554875; Facesoffungi number: FoF 04803

Type: INDIA, Rajasthanon, on dead wood, IMI 199276.

Possible distribution: India, Mexico, Puerto Rico.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Chouhan and Panwar (1980, as Helicosporium abuense) and Goos (1989, as Helicosporium abuense).

Notes: This taxon was described as Helicosporium abuense by Chouhan and Panwar (1980). Goos (1989) reexamined its type specimen and accepted Chouhan and Panwar’s identification. Tsui et al. (2006) provided its ITS sequence data. However, our phylogenetic analyses show that this taxon (CBS 101688) grouped within Neohelicosporium and shares a sister relationship to Neohelicosporium morganii (Fig. 2). Furthermore, its morphology does not tally within the taxonomic concepts of Helicosporium but fits well within Neohelicosporium and, therefore, we synonymize this taxon under Neohelicosporium abuense.


Neohelicosporium aurantiellum (Penz. & Sacc.) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Calonectria aurantiella Penz. & Sacc., Malpighia 11(11-12): 515 (1898) [1897]

≡ Tubeufia aurantiella (Penz. & Sacc.) Rossman, Mycotaxon 8(2): 489 (1979)

Index Fungorum: IF 554876; Facesoffungi number: FoF 04804

Type: JAVA, Tjibodas, superficial on dead wood, 1 March 1897, no. 126 (PAD).

Possible distribution: Brazil, Costa Rica, Honduras, Java, New Zealand, Peru, Venezuela.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Penzig and Saccardo (1897, as Calonectria aurantiella) and Rossman (1987, as Tubeufia aurantiella).

Notes: This taxon was described as Calonectria aurantiella by Penzig and Saccardo (1897). Rossman (1979) transferred it to the genus Tubeufia as T. aurantiella. Rossman (1987) reported several new records of T. aurantiella from Brazil, Honduras, New Zealand, Peru and Venezuela. Promputtha and Miller (2010) provided its ITS and LSU sequence data. Our phylogenetic analyses show that Tubeufia aurantiella (ANM 718) belongs to Neohelicosporium and shares a sister relationship to Neohelicosporium griseum, and support that they are distinct species (Fig. 2). Furthermore, the morphology of Tubeufia aurantiella differs from other Neohelicosporium by its yellow to luteous, globose to subglobose ascomata. Therefore, we synonymize it under Neohelicosporium aurantiellum.


Neohelicosporium griseum (Berk. & M.A. Curtis) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium griseum Berk. & M.A. Curtis, in Berkeley, Grevillea 3 (no. 26): 51 (1874) [non H. griseum (Bon.) Sacc. 1886].

= Helicosporium lumbricoides Sacc., Michelia 1(no. 1): 86 (1877)

= Helicosporium cinereum Peck, Ann. Rep. N.Y. St. Mus. nat. Hist. 33: 28 (1880)

= Helicomyces cinereus (Peck) Morgan, J. Cincinnati Soc. Nat. Hist. 15: 44 (1892)

= Helicosporium leptosporum Sacc., Syll. fung. (Abellini) 4: 559 (1886)

= Helicomyces leptosporus (Sacc.) Pound & Clem., Minn. bot. Stud. 1(Bulletin 9): 658 (1896)

= Helicomyces bellus Morgan, J. Cincinnati Soc. Nat. Hist. 15: 40 (1892)

Index Fungorum: IF 554877; Facesoffungi number: FoF 04805

Type: Unspecified.

Possible distribution: Austria, Belgium, Brazil, Britain, Canada (Ontario), China (Guangdong, Hainan, Heilongjiang, Hubei, Jilin, Taiwan), Cook Islands, Cuba, Czechia, Germany, Italy, Japan, Mexico, Morocco, New Guinea, New Zealand, Panama, Puerto Rico, South Africa, Switzerland, USA (Alabama, Indiana, Michigan, Ohio, Pennsylvania).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Goos (1989) and Zhao et al. (2007).

Notes: Matsushima (1971) synonymized Helicosporium griseum under H. lumbricoides. Goos (1989) treated H. cinereum, H. leptosporum and H. lumbricoides as H. griseum. Tsui et al. (2006) provided ITS and LSU sequence data for H. griseum (CBS 961.69 and UAMH 1694) and H. lumbricoides (JCM 9265). Zhao et al. (2007) accepted Goos’s treatment and reported several new records of H. griseum from China. Our phylogenetic result shows that two isolates of H. griseum (CBS 961.69 and UAMH 1694), H. lumbricoides (JCM 9265) and Helicomyces bellus (CBS 113542) cluster together within Neohelicosporium with good bootstrap support (Fig. 2). We compared their morphological characteristics provided by previous studies (Morgan 1892; Linder 1929; Talbot 1956; Ichinoe and Kume 1970; Matsushima 1971, 1980; Mercado-Sierra 1982; Goos 1985, 1989; Zhao et al. 2007) and found that they resemble each other. We also compared their DNA sequence data and there is only one base pair difference in their ITS and LSU sequence data respectively. Accordingly, these taxa should be one species. Furthermore, we compared their morphological features to other helicosporous species and their morphology fits well within the taxonomic concepts of Neohelicosporium and differs from Helicosporium and Helicomyces. Therefore, we synonymize Helicosporium griseum, H. lumbricoides and H. bellus to N. griseum because of the priority of “griseum” over others (Morgan 1892; Linder 1929; Talbot 1956; Ichinoe and Kume 1970; Matsushima 1971, 1980; Mercado-Sierra 1982; Goos 1985, 1989; Zhao et al. 2007).


Neohelicosporium morganii (Linder) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicoma morganii Linder [as ‘morgani’], Ann. Mo. bot. Gdn 16: 304 (1929)

= Helicoma berkeleyi Morgan, J. Cincinnati Soc. Nat. Hist. 15: 48 (1892)

= Helicoma violaceum G. Winter ex Linder, Ann. Mo. bot. Gdn 16: 303 (1929)

Index Fungorum: IF 554878; Facesoffungi number: FoF 04806

Type: USA, Ohio, Preston, on rotting wood of Juglans, June 12, 1887, A.P. Morgan (IA; CO-TYPES F, NY).

Possible distribution: Canada, China, Germany, USA (Ohio, Iowa).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Linder (1929, as Helicoma morgani), Goos (1986, as Helicoma morgani) and Zhao et al. (2007, as Helicoma morganii).

Notes: Linder (1929) synonymized Helicoma berkeleyi under H. morganii. Moore (1953) described this species as well. Goos (1986) reexamined its specimen materials. Tsui and Berbee (2006) provided its ITS and LSU sequence data (CBS 281.54). Zhao et al. (2007) reported a new record of H. morganii. However, our phylogenetic result shows that H. morganii (CBS 281.54) clusters with H. violaceum (CBS 222.58) within Neohelicosporium genus. Helicoma violaceum was introduced by Linder (1929). We compared their morphological features described by Linder (1929) and Goos (1986), and reckon that these two species should be treated as one species as they are morphologically identical. We also compared their morphological features to other Neohelicosporium species and their morphology fit well into the generic concept of Neohelicosporium but not to Helicoma. Therefore, we synonymize H. morganii and H. violaceum under Neohelicosporium morganii because of the priority of “morganii” over “violaceum” (Linder 1929).


Neohelicosporium myrtacearum (P.N. Singh & S.K. Singh) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium myrtacearum P.N. Singh & S.K. Singh, Current Research in Environmental & Applied Mycology 6(4): 251 (2016)

Index Fungorum: IF 554879; Facesoffungi number: FoF 04807

Type: INDIA, Maharashtra, Pune, Agharkar Research Institute campus (18°31′N, 73°55′E), on dead bark of Eucalyptus, 28 April 2015, coll. P.N. Singh, AMH 9748 (holotype), PNS-ARI 14 (isotype).

Known distribution: India.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Singh and Singh (2016, as Helicosporium myrtacearum).

Notes: This taxon was introduced by Singh and Singh (2016) as Helicosporium myrtacearum. However, compared to other Helicosporium species, its morphology does not fit into the generic concept of Helicosporium but to Neohelicosporium with its acropleurogenous conidia. Therefore, we synonymize it under Neohelicosporium as N. myrtacearum.


Neohelicosporium nizamabadense (P. Rag. Rao & D. Rao) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium nizamabadense P. Rag. Rao & D. Rao, Mycopath. Mycol. appl. 24(1): 34 (1964)

Index Fungorum: IF 554880; Facesoffungi number: FoF 04808

Type: INDIA, Nizamabad, on old bamboo thatch, 13 July 1963, Dev Rao, V.V.C.B.L. No. 252.

Possible distribution: Brazil, India, Mexico.

Habitat: Terrestrial.

Description: For a complete description of this taxon see Rao and Rao (1964, as Helicosporium nizamabadense) and Goos (1989, as Helicosporium nizamabadense).

Notes: This taxon was introduced by Rao and Rao (1964) as Helicosporium nizamabadense. It was characterized by hyaline to subhyaline conidiophores arising from repent mycelium, conidiogenous cells bearing tooth-like projections and acropleurogenous helicoid conidia coiled 2–3½ times. Goos (1989) accepted this taxon within Helicosporium. In the present study, we found all Helicosporium species having pale brown to dark brown conidiophores and pleurogenous conidia are phylogenetically supported, and H. nizamabadense should belong to Neohelicosporium. Therefore, we synonymize this taxon under Neohelicosporium as N. nizamabadense.


Neohelicosporium sympodiophorum (G.Z. Zhao, Xing Z. Liu & W.P. Wu) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium sympodiophorum G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 375 (2007)

Index Fungorum: IF 554881; Facesoffungi number: FoF 04809

Type: CHINA, Guangdong Province, Dinghu Mountain, on rotten wood of unidentified plant, 9 October 1998, Wenping Wu, WU1858A.

Known distribution: China (Guangdong).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Zhao et al. (2007, as Helicosporium sympodiophorum).

Notes: This taxon was introduced by Zhao et al. (2007) as Helicosporium sympodiophorum. However, we compare H. sympodiophorum to our new collections and other known Helicosporous species, its morphology fits well into the generic concept of Neohelicosporium rather than Helicosporium. This taxon resembles Neohelicosporium guangxiense (Lu et al. 2018) in conidia and conidiophores but can be recognized by its smaller conidia diameter (27–36 μm vs. 35–45 μm) and different number of conidial coils (3½–4 times vs. 2–2¾ times). Therefore, we transfer this taxon to Neohelicosporium as Neohelicosporium sympodiophorum.


Neohelicosporium taiwanense (C.H. Kuo & Goh) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium taiwanense C.H. Kuo & Goh, Mycol. Prog. 17 (5): 563 (2018)

Index Fungorum: IF 554882; Facesoffungi number: FoF 04810

Type: CHINA, Taiwan, Chiayi County, Juchi Township, on debarked wood submerged in a freshwater stream, 5 Feb. 2017, Chang-Hsin Kuo, NCYU-K1-1 (TNM F31001, deposited at National Museum of Natural Science, Taichung, Taiwan).

Known distribution: China (Taiwan).

Habitat: Aquatic.

Description: For a complete description of this taxon see Kuo and Goh (2018a, as Helicosporium taiwanense).

Notes: This taxon was described as Helicosporium taiwanense by Kuo and Goh (2018a). However, our phylogenetic result shows that this taxon (BCRC FU30841) grouped within the genus Neohelicosporium and shares a sister relationship to N. laxisporum and N. irregulare with high bootstrap support (Fig. 2). Furthermore, its morphology fits well into the generic concept of Neohelicosporium rather than Helicosporium. Therefore, we synonymize this taxon under Neohelicosporium as N. taiwanense.


Neohelicosporium vesiculiferum (A.C. Cruz & Gusmão) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium vesiculiferum A.C. Cruz & Gusmão, Mycotaxon 110: 55 (2009)

Index Fungorum: IF 554883; Facesoffungi number: FoF 04811

Type: BRAZIL, Bahia, Senhor do Bonfim, on dead wood branch, 25 September 2006, A.C.R. Cruz, HUEFS 129360.

Known distribution: Brazil.

Habitat: Terrestrial.

Description: For a complete description of this taxon see da Cruz et al. (2009, as Helicosporium vesiculiferum).

Notes: This taxon was introduced by da Cruz et al. (2009) as Helicosporium vesiculiferum. However, we compare H. vesiculiferum to our new collections and other known Helicosporous species and its morphology fits well into the generic concept of Neohelicosporium rather than Helicosporium. This taxon differs from Helicosporium species by its acropleurogenous conidia and integrated conidiogenous cells. Therefore, we transfer this taxon to the genus Neohelicosporium as N. vesiculiferum. Neohelicosporium vesiculiferum can be distinguished from other Neohelicosporium species by presence of a vesicle at conidiophore apex (da Cruz et al. 2009).

Other accepted Neohelicosporium species


Neohelicosporium aquaticum Y.Z. Lu, J.C. Kang & K.D. Hyde, Mycol. Progr.: 17 (5): 639 (2017)

Index Fungorum: IF 822057

Known distribution: China (Guangxi).

Habitat: Aquatic.

Notes: This taxon was introduced by Lu et al. (2018) based on phylogeny and morphological evidence.


Neohelicosporium fusisporum Jayasiri & K.D. Hyde, Studies in Fungi 2(1): 212 (2017)

Index Fungorum: IF 553908

Known distribution: Thailand.

Habitat: Terrestrial.

Notes: This taxon was introduced by Jayasiri et al. (2017) based on phylogeny and morphological evidence.


Neohelicosporium thailandicum Y.Z. Lu, J.C. Kang & K.D. Hyde, Mycol. Progr.: 17 (5): 641 (2017)

Index Fungorum: IF 822060

Known distribution: Thailand.

Habitat: Aquatic.

Notes: This taxon was introduced by Lu et al. (2018) based on phylogeny and morphological evidence.


Pleurohelicosporium Y.Z. Lu, J.C. Kang & K.D. Hyde, gen. nov

Index Fungorum: IF 554884; Facesoffungi number: FoF 04743

Etymology: “Pleurohelicosporium” referring to the pleurogenous helicoid conidia of this genus.

Saprobic on decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, pale brown. Mycelium mostly immersed, partly superficial, composed of branched, septate hyphae, pale brown, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, branched, septate, pale brown, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, sympodial, intercalary, cylindrical, with denticles, pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline to pale brown, smooth-walled.

Type species: Pleurohelicosporium parvisporum Y.Z. Lu, J.C. Kang & K.D. Hyde

Notes: The genus Pleurohelicosporium is morphologically similar to Neohelicosporium but phylogenetically apart from Neohelicosporium and other helicosporous genera. Pleurohelicosporium can be distinguished from Neohelicosporium by its pleurogenous conidia while the conidia of Neohelicosporium are acrogenous or acropleurogenous. In addition, Pleurohelicosporium shares a sister phylogenetic relationship to the genus Tamhinispora with good bootstrap support (Fig. 2), but their morphology are distinct and, therefore, Pleurohelicosporium gen. nov. is introduced in this study.


Pleurohelicosporium parvisporum Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554885; Facesoffungi number: FoF 04744; Fig. 50

Fig. 50
figure 50

Pleurohelicosporium parvisporum (MFLU 17–1124, holotype). a, b Colony on decaying wood. c, d Conidiophores. e, f Conidiogenous cells. g–l Conidia. m, n Colonies on PDA from above and below. o Umbonate colony surface on PDA from above. Scale bars: a, b = 100 µm, c, d = 50 µm, e–l = 10 µm

Full size image

Holotype: MFLU 17–1124

Etymology: “parvisporum” referring to the small helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a dry stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, pale brown. Mycelium composed of partly immersed, partly superficial, pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, branched, septate, 125–250 μm long, 4.5–6 μm wide, pale brown, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, sympodial, intercalary, cylindrical, with denticles, 9–13 μm long, 5–6 μm wide, pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 14–18 μm diam. and conidial filament 1.5–2.5 μm wide (\( \bar{x} \) = 16 × 2 μm, n = 20), 115–150 μm long, tightly coiled 2½–3¾ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, obviously umbonate, with rough surface, veined and wrinkle, edge undulate, reaching 15 mm in 2 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on decaying wood in a dry stream, 27 April 2017, Yong-Zhong Lu, TD08 (MFLU 17–1124, holotype; HKAS 100794, isotype), ex-type living cultures, MFLUCC 17–1982, TBRC.

Notes: Morphologically, Pleurohelicosporium parvisporum is similar to Neohelicosporium parvisporum and N. hyalosporum in conidial and conidiophore features but can be distinguished by its pleurogenous conidia, while the later two are acrogenous or acropleurogenous. Phylogenetically, P. parvisporum shares a sister relationship to Tamhinispora indica and T. srinivasanii with good bootstrap support (100% MLBS, 1.00 PP) (Fig. 2) and phylogeny supports that they are distinct species.


Pseudohelicomyces Y.Z. Lu, J.K. Liu & K.D. Hyde, gen. nov.

Index Fungorum: IF 554886; Facesoffungi number: FoF 04745

Etymology: “Pseudohelicomyces” referring to this genus not really “Helicomyces”.

Saprobic on woody substrata. Mycelium partly immersed, septate, branched hyphae. Sexual morph Ascomata superficial, seated on a subiculum, solitary, scattered, subglobose, clavate to obovate, coriaceous, pale brown to reddish-brown, with a central ostiole, without setae. Peridium composed of cells of textura angularis, with inner cells hyaline and outer cells pale brown to brown. Hamathecium comprising numerous, filiform, septate, branched, hyaline pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores overlapping fasciculate, fusiform, tapering towards rounded ends, straight or slightly curved, multi-septate, guttulate, hyaline, smooth-walled (Rossman 1977; Boonmee et al. 2014). Asexual morph Hyphomycetous, helicosporous. Conidiophores macronematous, mononematous, erect, cylindrical, branched, septate, subhyaline to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, intercalary or terminal, cylindrical, with denticles, subhyaline to brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, multi-septate, hyaline to pale brown, smooth-walled.

Type species: Pseudohelicomyces talbotii (Goos) Y.Z. Lu & K.D. Hyde

Notes: We introduced the new genus Pseudohelicomyces based on phylogenetic analyses and morphological data, to accommodate five species, viz. P. aquaticus, P. hyalosporus, P. indicus, P. paludosus and P. talbotii. Phylogenetically, these five species cluster together with good bootstrap support (Clade 2) (Fig. 2). Boonmee et al. (2014) considered that this group represented Helicomyces sensu stricto based on authentic sequences of Helicomyces roseus (CBS 283.51). However, we found that the morphology of isolate CBS 283.51 provided by Tsui et al. (2006) does not correspond well to the previous descriptions of Helicomyces roseus (Link 1809; Linder 1929; Goos 1985). Luo et al. (2017) also introduced five new Helicomyces roseus isolates based on their DNA sequence data which were identical to CBS 283.51 and their morphs were similar to those in previous studies. However, previous studies pointed out that the genus Helicomyces lacks or had reduced conidiophores formed as short, lateral branches of the repent mycelium (Link 1809; Linder 1929; Moore 1955; Matsushima 1971, 1975; Pirozynski 1972; Goos 1985; Zhao et al. 2007), but we found all isolates including our new isolates within Clade 2 are obviously distinct from Helicomyces species in conidiophores and conidia. Therefore, we consider that Helicomyces roseus (CBS 283.51) have been wrongly identified. Furthermore, our new isolates in Clade 4 (Fig. 2) correspond morphologically to Helicomyces in conidiophores, conidiogenous cells and conidia. We therefore treat Clade 4 as Helicomyces and Clade 2 as Pseudohelicomyces.


Pseudohelicomyces aquaticus Y.Z. Lu, Boonmee & K.D. Hyde, sp. nov.

Index Fungorum: IF 554887; Facesoffungi number: FoF 04746; Fig. 51

Fig. 51
figure 51

Pseudohelicomyces aquaticus (MFLU 17–1183, holotype). a Colony on decaying wood. b–d Conidiophores. e–h Conidiogenous cells. i–l Conidia. m, n Colonies on PDA from above and below. Scale bars: a = 100 µm, b = 50 µm, c, d = 20 µm, e–l = 10 µm

Full size image

Holotype: MFLU 17–1183

Etymology: “aquaticus” referring to aquatic habitat.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, branched, ramose, septate, 50–170 μm long, 3.5–5 μm wide, hyaline to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, truncate at apex after conidial secession, 8–16 μm long, 2.5–4.5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 15–20 μm diam. and conidial filament 1.5–3 μm wide (\( \bar{x} \) = 17 × 2 μm, n = 20), 90–130 μm long, indistinctly multi-septate, coiled 2½–3½ times, becoming loosely coiled in water, guttulate, hyaline to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge undulate, reaching 19 mm in 3 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Krabi, Muang, Khao Khram, Ban Nong Jig, Tha Pom Klong Song Nam, on submerged decaying wood in freshwater stream, 16 December 2015, Saranyaphat Boonmee, TP01–1 (MFLU 17–1183, holotype), ex-type living cultures, MFLUCC 16–0234, TBRC 8903.

Notes: Morphologically, Pseudohelicomyces aquaticus is similar to Neohelicosporium parvisporum (Lu et al. 2018) in conidia but can be distinguished by conidiophores and conidiogenous cells. The conidiophores of N. parvisporum are hyphae-like with many tiny denticles arising laterally as sporogenous conidiogenous loci, but P. aquaticus lacks these characteristics. The conidiogenous cells of P. aquaticus are terminal or intercalary, with an irregular-cylindrical shape, truncate at apex after conidial secession. Besides, the conidia of P. aquaticus are acropleurogenous, but those of N. parvisporum are pleurogenous. Furthermore, H. aquaticus differs from Helicomyces species in having obviously smaller conidia as well as an irregular-cylindrical shaped conidiogenous cells. Phylogenetically, P. aquaticus constitutes a well supported independent lineage within Pseudohelicomyces and support it as a distinct species (Fig. 2).


Pseudohelicomyces hyalosporus Y.Z. Lu, J.K. Liu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554888; Facesoffungi number: FoF 04812

Type: CHINA, Yunnan Province, saprobic on decaying wood submerged in a stream in Cangshan Mountain, March 2014, Z.L. Luo HKAS 83995 (holotype), ex-type living cultures, MFLUCC 15–0343.

Etymology: “hyalosporus” referring to hyaline helicoid conidia of this fungus.

Known distribution: China, Switzerland.

Habitat: Aquatic.

Descriptions: For a complete description of this fungus see Luo et al. (2017, as Helicomyces roseus).

Notes: This taxon was introduced as Helicomyces roseus by Luo et al. (2017) based on its morphological similarities to H. roseus and its DNA sequence data are identical to H. roseus (CBS 283.51). However, the morphology of isolate CBS 283.51 does not tally to previous descriptions of H. roseus in conidiophores and conidia (Link 1809; Linder 1929; Goos 1985). Therefore, we consider that H. roseus CBS 283.51 have been wrongly identified. Furthermore, six isolates of H. roseus form a subclade which share a sister relationship to Pseudohelicomyces talbotii with good bootstrap support (99% MLBS, 1.00 PP) (Fig. 2). We also found those isolates in Clade 4 correspond to Helicomyces, thus, we reappraise these six isolates as Pseudohelicomyces hyalosporus. We designate the specimen HKAS 83995 as holotype as Luo et al. (2017) designated this as reference specimen. Pseudohelicomyces hyalosporus differs to other Pseudohelicomyces by having shorter conidiophores and larger conidia.

New combinations of Pseudohelicomyces

Pseudohelicomyces indicus (P. Rag. Rao & D. Rao) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium indicum P. Rag. Rao & D. Rao, Mycopath. Mycol. appl. 24(1): 32 (1964)

Index Fungorum: IF 554889; Facesoffungi number: FoF 04813

Type: INDIA, Nizamabad, on old bamboo thatch, 1 September 1963, D.R., in the Herbarium hyderabadense, V.V.C.B.L. No. 243.

Possible distribution: Australia, India.

Habitat: Terrestrial.

Descriptions: For a complete description of this fungus see Rao and Rao (1964, as Helicosporium indicum).

Notes: This taxon was introduced as Helicosporium indicum by Rao and Rao (1964). Pirozynski (1972) regarded that Helicosporium indicum is related to Drepanospora pannosum. Goos (1989) accepted this taxon within the Helicosporium. Tsui et al. (2006) provided its ITS and LSU sequence data (CBS 374.93). Boonmee et al. (2014) pointed out that H. indicum (CBS 374.93) clustered within Helicomyces in their multi-gene phylogeny tree, and they renamed it as Helicomyces indicum but did not synonymize it (Boonmee et al. 2014). Subsequently, there have been many phylogenetic studies dealing with Tubeufiaceae which followed Boonmee’s treatment and named Helicosporium indicum (CBS 374.93) as Helicomyces indicum (CBS 374.93) (Hyde et al. 2016a; Brahamanage et al. 2017; Chaiwan et al. 2017; Lu et al. 2017a, b, 2018; Luo et al. 2017; Phookamsak et al. 2018). However, its valid name still remained as Helicosporium indicum. In the present study, our multi-gene phylogenetic result shows that H. indicum (CBS 374.93) groups within Pseudohelicomyces. Furthermore, its morphology is similar to Pseudohelicomyces talbotii and does not tally with the generic concept of Helicosporium. Therefore, we synonymize Helicosporium indicum under Pseudohelicomyces as P. indicus.


Pseudohelicomyces paludosus (P. Crouan & H. Crouan) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Nectria paludosa P. Crouan & H. Crouan, Florule Finistère (Paris): 38 (1867)

≡ Ophionectria paludosa (P. Crouan & H. Crouan) Sacc., Michelia 1(no. 3): 323 (1878)

≡ Tubeufia paludosa (P. Crouan & Crouan) Rossman, Mycologia 69(2): 383 (1977)

≡ Helicomyces paludosus (P. Crouan & H. Crouan) Boonmee & K.D. Hyde [as ‘paludosa’], Fungal Diversity 68: 274 (2014)

= Helicosporium phragmitis Höhn., Annales Mycologici 3 (4): 338 (1905)

= Ophionectria anceps (Penz. & Sacc.) Höhn., Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften Math.-naturw. Klasse Abt. I 128: 562 (1919)

= Tubeufia anceps Penz. & Sacc., Malpighia 11: 518 (1897)

= Tubeufia coronata Penz. & Sacc., Malpighia 11: 517 (1897)

Index Fungorum: IF 554890; Facesoffungi number: FoF 04814

Type: USA, Tennessee, Blount Co., Great Smoky Mountains National Park, 25 mi W Gatlinburg, Cades Cove, Gregory Ridge Trail, on rotten wood of unidentified angiosperm, A.Y. Rossman, 6 September 2005, BPI 871087 (epitype).

Possible distribution: Bermuda, Brazil, Britain, Canada (Ontario), Colombia, Costa Rica, Ecuador, France, French Guiana, Guyana, Ireland, Japan, Java, Mexico, Morocco, New Zealand, Panama, Peru, USA (Florida, Ohio, Tennessee), Venezuela, Wales.

Habitat: Terrestrial.

Descriptions: For a complete description of this fungus see Crouan and Crouan (1867, as Nectria paludosa), Saccardo (1878, as Ophionectria paludosa), Rossman (1977, as Tubeufia paludosa) and Boonmee et al. (2014, as Helicomyces paludosus).

Notes: This taxon was introduced as Nectria paludosa by Crouan and Crouan (1867). Saccardo (1878) synonymized it under Ophionectria paludosa. Rossman (1977) synonymized it together with Helicosporium phragmitis, Ophionectria anceps, Tubeufia anceps and T. coronata under T. paludosa. Boonmee et al. (2014) synonymized it under Helicomyces paludosus based on phylogenetic evidence. Our phylogenetic result shows that H. paludosus (CBS 120503) groups within Pseudohelicomyces and shares a sister relationship to P. indicus with good bootstrap support (Fig. 2). We therefore synonymized Helicomyces paludosus under Pseudohelicomyces paludosus.


Pseudohelicomyces talbotii (Goos) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium talbotii Goos, Mycologia 81(3): 368 (1989)

≡ Helicosporium ramosum Talbot, Bothalia 6:489–500. 1956

Index Fungorum: IF 554891; Facesoffungi number: FoF 04747; Fig. 52

Fig. 52
figure 52

Pseudohelicomyces talbotii (MFLU 17–1106, reference specimen). a Colony on decaying wood. b–e Conidiophores. f–h Conidiogenous cells. i–o Conidia. p, q Colonies on PDA from above and below. Scale bars: a, b = 100 µm, c–e = 50 µm, f–o = 20 µm

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Type: South Africa, Pretoria, Fountains, on dead wood, November 1951, P.H.B. Talbot, No. 40546.

Possible distribution: China, Japan, Mexico, South Africa, Thailand.

Habitat: Aquatic, Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, mostly branched, septate, 25–260 μm long, 3.5–5 μm wide, subhyaline to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal or intercalary, cylindrical, with denticles, 7–16 μm long, 3–5 μm wide, subhyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, indistinctly multi-septate, 17–23 μm diam. and conidial filament 2–3 μm wide (\( \bar{x} \) = 20 × 2.5 μm, n = 20), 90–115 μm long, coiled 1½–2½ times, becoming loosely coiled in water, guttulate, hyaline to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge undulate, reaching 21 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 25 March 2017, Yong-Zhong Lu, CR32 (MFLU 17–1106, reference specimen designated here; KAS 100776), living culture, MFLUCC 17–2021.

Notes: This taxon was initially described by Talbot (1956) as Helicosporium ramosum. Goos (1989) gave the name Helicosporium talbotii because H. ramosum was a later homonym of H. ramosum. Tsui et al. (2006) provided ITS and LSU sequence data for this taxon (H. talbotii MUCL 33010), but with no morphological descriptions. Zhao et al. (2007) described a new record of H. talbotii and provided its detailed descriptions and illustrations. Boonmee et al. (2014) mentioned that H. talbotii (MUCL 33010) clustered within Helicomyces in their phylogeny and they renamed it as Helicomyces talbotii but did not synonymize it (Boonmee et al. 2014). Other phylogenetic studies on the Tubeufiaceae also named Helicosporium talbotii (MUCL 33010) as Helicomyces talbotii (MUCL 33010) (Hyde et al. 2016a; Brahamanage et al. 2017; Chaiwan et al. 2017; Lu et al. 2017b, 2018; Luo et al. 2017; Phookamsak et al. 2018). However, there is still some taxonomic confusion as its valid name still remained as Helicosporium talbotii. In the present study, our multi-gene phylogenetic result shows that H. talbotii (MUCL 33010) clusters together with our new isolate MFLUCC 17–2021 within Pseudohelicomyces with high bootstrap support (Fig. 2), and support that they should be the same species. We compared our new isolate to H. talbotii described by Talbot (1956), Goos (1989) and Zhao et al. (2007). They resemble each other in features of conidiophores, conidiogenous cells and conidia. We also compared the sequence data of MUCL 33010 with our new isolate MFLUCC 17–2021 and noted there is only one base pair difference and three missing gaps between MUCL 33010 and MFLUCC 17–2021 in their ITS sequence data and no difference in LSU (No protein gene data are available for MUCL 33010). Hence, we identify our new isolate and H. talbotii (MUCL 33010) as the same species, and synonymize it under Pseudohelicomyces talbotii. As the sequenced collection of Pseudohelicomyces talbotii were not sequenced from the type specimen and were not detailed illustrated as well, we designated our new collection MFLU 17–1106 as a reference specimen.


Pseudohelicoon Y.Z. Lu & K.D. Hyde, gen. nov.

Index Fungorum: IF 554919; Facesoffungi number: FoF 04748

Etymology: “Pseudohelicoon” referring to this genus not really “Helicoön”.

Saprobic on submerged decaying woody substrate. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on natural substratum dark-brown, somewhat glistening, effuse. Mycelium partly immersed but mostly superficial, consisting of branched hyphae and short conidiophores bearing conidia, pale yellowish-brown, smooth, branched, closely septate, slightly constricted at the septa. Conidiophores macronematous, mononematous, cylindrical, erect, straight, arising as short branches more or less at right angles to the subtending hyphae, yellowish-brown or somewhat darker than the subtending hyphae, unbranched, aseptate, smooth-walled. Conidiogenous cells monoblastic, integrated, terminal, determinate. Conidia solitary, dry, acrogenous, medium brown, helicoid, smooth, distinct multiseptate, slightly constricted at the septa, tightly coiled 7−13 times in a clockwise direction to form a subglobose or broadly elliptical body, usually incorporated with mucilaginous substances such that no gaps are visible between adjacent coils, non-hygroscopic; conidial secession schizolytic at the delimitating septum of the conidiogenous cell, giving rise to a short pedicel at the base (Goh and Hyde 1996; Goh and Kuo 2018).

Type species: Pseudohelicoon subglobosum (Goh & C.H. Kuo) Y.Z Lu & Hyde

Notes: The genus Helicoön was established by Morgan (1892) to accommodate helicosporous species developing nonproliferating, ellipsoidal to doliiform conidia. However, the representative species of Helicoön occurred in different ordinal lineages: the type species, H. sessile, arose from the Orbiliales (Goh and Kuo 2018); H. gigantisporum and H. subglobosum clustered within the Tubeufiales (Goh and Kuo 2018); H. richonis grouped within the Pleosporales (Tsui and Berbee 2006; Goh and Kuo 2018); H. fuscosporum and H. maioricense within the Venturiales; H. farinosum within the Pleurotheciales (Réblová et al. 2016; Goh and Kuo 2018). Given the polyphyletic nature of Helicoön, we suggest that there is a need to revisit the taxonomy with additional support from new collections and DNA sequence data. To avoid further taxonomic confusion herein, we introduce the new genus Pseudohelicoon to accommodate H. gigantisporum and H. subglobosum where our phylogeny confirms that they belong to the family Tubeufiaceae (Goh and Kuo 2018). However, we do not transfer other Helicoön species to this genus.

New combinations of Pseudohelicoon

Pseudohelicoon gigantisporum (Goh & K.D. Hyde) Y.Z. Lu & J.K. Liu, comb. nov.

≡ Helicoön gigantisporum Goh & K.D. Hyde, Mycol. Res. 100(12): 1487 (1996)

Index Fungorum: IF 554920; Facesoffungi number: FoF 04815

Type: Australia, north Queensland, Mt Lewis, on submerged wood in small stream, May 1995, K.D. Hyde & T.M. Hyde, BRIP 23200.

Known distribution: Australia.

Habitat: Aquatic.

Descriptions: For a complete description of this fungus see Goh and Hyde (1996, as Helicoön gigantisporum).

Notes: This taxon was introduced as Helicoön gigantisporum by Goh and Hyde (1996). We synonymize it under Pseudohelicoon gigantisporum based on phylogenetic evidence. Pseudohelicoon gigantisporum shares a sister relationship to H. subglobosum with good bootstrap support within the family Tubeufiaceae (Clade 15) (Fig. 2).


Pseudohelicoon subglobosum (Goh & C.H. Kuo) Y.Z. Lu & Hyde, comb. nov.

≡ Helicoön subglobosum Goh & C.H. Kuo, Phytotaxa 346 (2): 145 (2018)

Index Fungorum: IF 554921; Facesoffungi number: FoF 04816

Type: China, Taiwan, Chiayi County, Juchi Township, on decaying wood submerged in a freshwater stream, 5 February 2017, Chang-Hsin Kuo, TNM F31003 (holotype).

Known distribution: China (Taiwan).

Habitat: Aquatic.

Descriptions: For a complete description of this fungus see Goh and Kuo (2018, as Helicoön subglobosum).

Notes: This taxon was introduced as Helicoön subglobosum by Goh and Kuo (2018). We synonymize it under Pseudohelicoon subglobosum based on phylogenetic evidence.


Thaxteriellopsis Sivan., Panwar & S.J. Kaur, Kavaka 4: 39 (1977) [1976]

Index Fungorum: IF 5409

Saprobic on decaying woody substrata. Sexual morph Ascomata superficial, seated on a subiculum, solitary, scattered, globose to subglobose, reddish-brown to dark brown. Setae multi-septate, thick-walled, brown to black, straight or slightly curved, covered with the whole ascomata. Peridium thick-walled, composed of several layers cells of textura angularis, with inner cells brown and outer cells dark brown. Hamathecium comprising numerous, filiform, septate, branched pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, pedicellate, apically rounded. Ascospores 2–3-seriate, fusiform to clavate, tapering towards rounded ends, straight or slightly curved, 5-septate, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Conidiophores macronematous, mononematous, erect, arising as lateral branches from creeping hyphae, cylindrical, branched or unbranched, septate, pale brown to dark brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, pale brown to brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, tapering towards apex, rounded at tip, multi-septate, hyaline, smooth-walled.

Type species: Thaxteriellopsis lignicola Sivan., Panwar & S.J. Kaur, Kavaka 4: 39 (1977)

Notes: Thaxteriellopsis was introduced by Sivanesan et al. (1976) with Thaxteriellopsis lignicola as the type species. Crane et al. (1998) transferred T. lignicola to Chaetosphaerulina. Boonmee et al. (2011) reexamined the holotype of T. lignicola (IMI 197065) and designated an epitype (MFLU 10–0057) and retained Thaxteriellopsis as a distinct genus within Tubeufiaceae. The type species, T. lignicola, is the only species accepted in this genus (Boonmee et al. 2011, 2014). Doilom et al. (2017) introduced an asexual record of T. lignicola based on phylogenetic evidence. In this study, we report the new records of T. lignicola with new morphological characteristics and more detailed asexual morph features derived from single spore isolations.


Thaxteriellopsis lignicola Sivan., Panwar & S.J. Kaur, Kavaka 4: 39 (1977) [1976]

≡ Chaetosphaerulina lignicola (Sivan., Panwar & S.J. Kaur) J.L. Crane, Shearer & M.E. Barr, Can. J. Bot. 76(4): 608 (1998)

Index Fungorum: IF 324512; Facesoffungi number: FoF 01866; Figs. 53 and 54

Fig. 53
figure 53

Thaxteriellopsis lignicola (MFLU 17–1168). a, b Superficial ascomata on substrate. Note ascomata surrounded by brown to black setae. c Ascoma. d Peridium. e Seta. f Asci with hamathecium. g–i Asci. j–m Ascospores. Scale bars: a, b = 500 µm, c = 200 µm, d, j–m = 20 µm, e–i = 50 µm

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Fig. 54
figure 54

The asexual morph of Thaxteriellopsis lignicola (from sexual morph’s cultures). a Germinating ascospore. b, c Colonies on PDA from above and below. c Colony on PDA from above. e, h, i Conidiophores with attached conidia. f, g Conidiophores. j–o Conidia. Scale bars: a, i–o = 10 µm, d = 200 µm, e = 50 µm, f–h = 20 µm

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Known distribution: India, Thailand.

Habitat: Aquatic, Terrestrial.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Ascomata 235–320 μm high, 280–345 μm wide, superficial, solitary and scattered, globose to subglobose, shiny, dark brown to black, obviously collapsed when dry, setose, coriaceous. Setae 110–230 μm long, covering the whole ascomata, brown to dark brown, septate, unbranched, apically rounded, thick-walled. Peridium 23–34 μm thick, multi-layered, outer layer comprising pale brown to dark brown cells of textura angularis, inner layer comprising hyaline to pale brown cells of textura angularis. Hamathecium comprising numerous, 1.5–3 μm wide, filiform pseudoparaphyses. Asci 110–185 μm long, 15–19 μm wide (\( \bar{x} \) = 141 × 17 μm, n = 20), 8-spored, bitunicate, cylindrical to clavate, apically rounded, with a 30–55 μm long pedicel. Ascospores 24–40 μm long, 6.5–7.5 μm wide (\( \bar{x} \) = 34 × 7 μm, n = 50), 2–3-seriate, clavate to fusiform, upper part broad, slightly curved, ends rounded, 5-septate, hyaline, smooth-walled. Asexual morph Hyphomycetous, helicosporous. Conidiophores micronematous, mononematous, erect, cylindrical, arising as lateral branches from creeping hyphae, branched or unbranched, septate, slightly constricted at septa so as to give a monilioid appearance, 20–95 μm long, 6–7 μm wide, the lower part brown and the upper part pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, 9–11 μm long, 5.5–7 μm wide, pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, solitary, 12–18 μm diam. and conidial filament 5–7 μm wide in the broadest part (\( \bar{x} \) = 14 × 6 μm, n = 20), tapering to 2.5–3 μm wide near apex and base, 35–45 μm long, tightly coiled 1¼–1½ times, not becoming loose in water, rounded at tip, 6-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 21 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on decaying wood in a freshwater stream, 28 November 2015, Saranyaphat Boonmee and Yong-Zhong Lu, TUB04 (MFLU 17–1166 = HKAS 100722), living culture, MFLUCC 16–0024; Ibid., TUB05–2 (MFLU 17–1168), living culture, MFLUCC 16–0026.

Notes: Our two new collections of Thaxteriellopsis lignicola are morphologically different from other previously described specimens. The ascomata of our new collections are obviously collapsed when dried and larger sized than others. Its setae and asci are longer than those of previously described records (Boonmee et al. 2011, 2014). The asexual morph was found from the cultures. Its conidia are typical helicoma-like but conidiophores are distinct. Phylogenetically, our two new isolates and other five known isolates formed one clade (Clade 24) and the phylogenetic result shows some slight divergence between them. However, they should be the same species (Fig. 2). We compare our isolates to the type strain of T. lignicola and there are 1 bp, 6 bp, 2 bp differences in their ITS, RPB2 and TEF1α sequence data respectively, which may explain their slight phylogenetic divergence. However, we could not identify any morphological features to separate our two isolates and those fewer gene base pair changes are not enough to indicate they are different species, and thus, we identify our two new isolates as T. lignicola.


Tubeufia Penz. & Sacc., Malpighia 11(11–12): 517 (1898)

Index Fungorum: IF 5635

Saprobic on decaying woody substrates in terrestrial and aquatic habitats, widespread in temperate and tropical regions. Sexual morph (1) Ascomata superficial, seated on a subiculum, spherical to clavate-obovate, oval to ellipsoid, without setae, coriaceous, with a central ostiole, white to brown. Ostiole single, central. Peridium comprising pale brown cells of textura angularis, and textura prismatica subhyaline cells at innermost layers. Hamathecium comprising numerous filiform, septate, branched, hyaline pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, saccate or cylindric-clavate, with or without an ocular chamber, hyaline, smooth-walled. Ascospores fasciculate in ascus, filiform, multi-septate, hyaline to pale brown, smooth-walled; (2) Ascomata superficial, seated on a subiculum, spherical to clavate-obovate, oval to ellipsoid, setose, coriaceous, with a central ostiole, dark brown to black. Ostiole single, central. Setae dense, flexuous, covering the whole ascoma, unbranched, rounded at apical end, septate, dark brown. Peridium comprising dark brown cells of textura angularis, with innermost part comprising thin layers of hyaline to pale brown cells of textura subprismatica. Hamathecium comprising numerous filiform, septate, branched, hyaline pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical, rounded the apex, with an ocular chamber, sessile, hyaline, smooth-walled. Ascospores fasciculate, broad fusiform, cylindrical to long subfusiform, slightly curved, tapering towards rounded ends, multi-septate, guttulate, hyaline, smooth-walled. Asexual morph (1) Hyphomycetous, helicosporous. Conidiophores macronematous, mononematous, erect, flexuous, cylindrical, branched or unbranched, septate, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal and/or intercalary, cylindrical, with denticles, or truncate at apex after conidial secession, hyaline to pale brown, smooth-walled. Conidia solitary, acrogenous or acropleurogenous, helicoid, rounded at the tip, coiled number of times when tightly coiled, becoming loosely in water, multi-septate, hyaline, smooth-walled; (2) Hyphomycetous, dictyosporous. Conidiophores lacking. Conidiogenous cells holoblastic, monoblastic, integrated, cylindric, apical, pale brown. Dictyospores acrogenous, carbonaceous, friable, solitary, variable in shape, globose to subglobose, ovoid to irregular, dictyoseptate, verrucose, brown to black.

Type species: Tubeufia javanica Penz. & Sacc., Malpighia 11(11–12): 517 (1898) [1897]

Notes: The genus Tubeufia was introduced by Penzig and Saccardo (1897). Previous studies reported that Tubeufia was characterized by white, cream-pink to brownish, vertically oblong to ovoid ascomata, cylindrical asci and cylindrical, fusiform, vermiform, multi-septate ascospores (Penzig and Saccardo 1897, 1904; Barr 1979, 1980; Rossman 1987; Kodsueb et al. 2004, 2006; Boonmee et al. 2011, 2014). Recently, Dai et al. (2017) introduced a new species, Tubeufia longiseta which is morphologically quite different from other known Tubeufia species. Lu et al. (2017b) also reported a new species T. latispora which is morphologically similar to T. longiseta but can be distinguished by size. In this study, we report two new sexual morphs of Tubeufia, viz. T. bambusicola and T. sessilis, whose morphology resemble T. latispora and T. longiseta in ascomata, asci and ascospores features. The main differences between these four species and other known Tubeufia sexual morphs are: (1) they have dense, flexuous setae covering the whole ascomata but not in others; (2) they have short but wider ascospores whereas in others obviously longer but narrower spores (Penzig and Saccardo 1897, 1904; Barr 1979, 1980; Rossman 1987; Kodsueb et al. 2004, 2006; Boonmee et al. 2011, 2014; Dai et al. 2017; Lu et al. 2017b). However, our phylogenetic analyses strongly support these four morphologically distinct fungi within Tubeufia. Therefore, we reappraised the taxonomy for Tubeufia in this study.

The close phylogenetic relationships between T. chlamydospora, T. dictyospora and other Tubeufia species are unexpected but supported strongly based on phylogeny.

Furthermore, the helicosporous asexual morph of Tubeufia are also of various shape. For example, T. machaerinae lacks conidiophores while other helicosporous hyphomycetes in Tubeufia have distinct conidiophores; T. abundata is having abundant, branched and long conidiophores while T. arctata has rarely unbranched, short conidiophores; T. sympodihylospora has repeatedly geniculate conidiogenous cells which are truncate at apex after conidial secession while T. chiangmaiensis is with conspicuous denticles; T. parvispora has conidial filament 2–3 μm wide while in T. krabiensis it is 5.5–8 μm wide; T. krabiensis and T. machaerinae have conidia tightly coiled that not becoming loose in water while conidia of T. sympodilaxispora and T. tratensis are loosely coiled and will become loose in water.

To conclude, both asexual and sexual morphs of Tubeufia vary in shape. It is very difficult to identify them without DNA sequence data. Many previous described Tubeufia species lack DNA sequence data and new collections and molecular data are needed to clarify their taxonomy.

In this paper, we introduce 45 new isolates, 17 new species and six new combinations in the genus Tubeufia, revisit the taxonomy of Helicomyces roseus (BCC 8808) and Helicomyces torquatus (BCRC FU30844), identify the isolates Tubeufia sp. (BCC 3580) and Tubeufia sp. (MLTS 119), and emend the ex-type DNA sequence data of Tubeufia hyalospora (MFLUCC 15–1250). Besides, Helicoma sp. (BCC 3512), Helicomyces roseus (BCC 3381) and Helicoma perelegans (ATCC 22621) are renamed as Tubeufia sp. to represent that they need further studies to solve their identification problems. We accept 50 species within Tubeufia including the new species and new combinations. Tubeufia helicomyces is excluded from this genus (Fig. 55).

Fig. 55
figure 55figure 55

Phylogram generated from maximum likelihood analysis based on combined ITS, LSU and TEF1α sequence data for species of Tubeufia (with Neohelicosporium aquaticum and Neohelicosporium parvisporum as outgroup). Eighty-two strains are included in the combined sequence analyses which comprise 2391 characters with gaps (643 characters for ITS, 836 for LSU, 912 for TEF1α). Single gene analyses were also performed and tree topology and clade stability compared. The best scoring RAxML tree with a final likelihood value of − 11146.670686 is presented. RAxML bootstrap support values equal to or greater than 75% are given before the forward slash. Maximum parsimony bootstrap support values equal to or greater than 75% are given after the forward slash. Branches with bayesian posterior probability equal to or higher than 0.95 are in bold. Hyphen (‘-’) indicates a value lower than 75% for RAxML and Maximum parsimony. Newly generated sequences are in bold. Strains isolated from the holotype, epitype, paratype and reference specimens are indicated in with a red superscript H, E, P and R, respectively

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Tubeufia abundata Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554895; Facesoffungi number: FoF 04749; Fig. 56

Fig. 56
figure 56

Tubeufia abundata (MFLU 17–1213, holotype). a, b Colony on decaying wood. c–g Conidiophores. h–j Conidiogenous cells. k–o Conidia. p, q Colonies on PDA from above and below. Scale bars: a, b = 100 µm, c–g = 50 µm, h–o = 20 µm

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Holotype: MFLU 17–1213

Etymology: “abundata” referring to the abundant conidiophores.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, abundant, cylindrical, branched, septate, 55–225 μm long, 5–7 μm wide, hyaline to brown, smooth-walled. Conidiogenous cells comprising two types: (1) holoblastic, monoblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, 12–22 μm long, 4–5 μm wide, hyaline to pale brown, smooth-walled; (2) holoblastic, monoblastic, integrated, sympodial, intercalary, cylindrical, with denticles, 8.5–11 μm long, 5–7 μm wide, pale brown to brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 25–40 μm diam. and conidial filament 3.5–4.5 μm wide (\( \bar{x} \) = 32 × 4 μm, n = 20), 180–210 μm long, tightly coiled 2¼–3 times, becoming loosely coiled in water, multi-septate, up to 26-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with a center slight umbonate surface, edge entire, reaching 39 mm in one month at 28 °C, pale brown to brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 25 March 2017, Yong-Zhong Lu, CR43 (MFLU 17–1213, holotype; HKAS 100779, isotype), ex-type living culture, MFLUCC 17–2024.

Notes: Tubeufia abundata can be easily distinguished from other helicosporous hyphomycetes by its abundant conidiophores with non-hygroscopic helicoid conidia. Most conidia of T. abundata are acrogenous on the terminal cylindrical conidiogenous cells which are truncate at apex after conidial secession, but a few of them are pleurogenous and develop from intercalary conidiogenous cells with tiny tooth-like protrusions arising laterally from conidiophores. Phylogenetically, T. abundata clusters within Tubeufia with high bootstrap support and support that it is a distinct species (Fig. 55).


Tubeufia aquatica Z.L. Luo, Bhat & K.D. Hyde, Cryptog. Mycol. 38(1): 44 (2017)

Index Fungorum: IF 818827; Facesoffungi number: FoF 02649; Fig. 57

Fig. 57
figure 57

Tubeufia aquatica (MFLU 17–1091). a Colony on decaying wood. b, c Conidiophores with attached conidia. d–f Conidiogenous cells. g–k Conidia. l Germinating conidium. m, n Colonies on MEA from above and below. Scale bars: a = 100 µm, b = 20 µm, c–l = 10 µm

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Holotype: MFLU 16–2544

Known distribution: China (Yunnan), Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, unbranched, 0–1-septate, 18–40 μm long, 4–5 μm wide, pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, denticulate, 12–23 μm long, 4–5 μm wide, pale brown, smooth-walled. Conidia solitary, acrogenous, helicoid, rounded at tip, 21–25 μm diam. and conidial filament 4.5–6 μm wide (\( \bar{x} \) = 22 × 5 μm, n = 50), 80–115 μm long, coiled 1½–2¼ times, not becoming loose in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, irregular, with flat surface, edge undulate, reaching 22 mm in 4 weeks at 28 °C, pale brown to brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR08 (MFLU 17–1091 = HKAS 100761), living cultures, MFLUCC 17–1794, TBRC.

Notes: Phylogenetically, our newly obtained isolate nests within Tubeufia aquatica (MFLUCC 16–1249 and DLUCC 0574) with high bootstrap support (Fig. 55), which indicates that they are conspecific. Therefore, we identify our new collection as Tubeufia aquatica. It is necessary to point out that our new collection is characterized by 0–1-septate conidiophores which is morphologically distinct from the previously described T. aquatica (Luo et al. 2017).


Tubeufia bambusicola Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554896; Facesoffungi number: FoF 04750; Fig. 58

Fig. 58
figure 58

Tubeufia bambusicola (MFLU 17–1111, holotype). a Superficial ascomata on substrate. Note ascomata surrounded by black setae. b Ascoma. c Seta. d Peridium. e–g Asci. h–n Ascospores. o Germinating ascospore. p, q Colonies on PDA from above and below. Scale bars: a = 500 µm, b = 200 µm, c = 100 µm, d–g = 50 µm, h–o = 20 µm

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Holotype: MFLU 17–1111

Etymology: with reference to its occurrence on Bambusa sp.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on dead bamboo in a mountain. Sexual morph Ascomata 200–395 μm high × 165–230 μm diam. superficial, gregarious, ellipsoidal, subglobose, setose, coriaceous, with a central ostiole, dark brown to black. Ostiole single, central. Setae 250–355 (–480) × 3–4 μm (\( \bar{x} \) = 287 × 3.5 μm, n = 20), dense, flexuous, covering the whole ascoma, unbranched, rounded at apical end, septate, dark brown. Peridium 22–29 μm wide, composed cells of textura angularis, dark, with innermost part comprising thin layers of hyaline to pale brown cells of textura subprismatica. Hamathecium comprising numerous filiform, septate, branched pseudoparaphyses. Asci 110–145 (–187) × 13–18 μm (\( \bar{x} \) = 128 × 15.5 μm, n = 20), 8-spored, bitunicate, cylindrical, rounded at apex, with an ocular chamber, thick-walled, sessile. Ascospores 50–73 × 5–7 μm (\( \bar{x} \) = 61 × 6 μm, n = 50), 2–3-seriate, broad fusiform, cylindrical to long subfusiform, elongate, slightly curved, tapering towards rounded ends, up to 21-septate, verrucose, guttulate, hyaline. Asexual morph Undetermined.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing on PDA, circular, with flat surface, edge undulate, reaching 36 mm in three weeks at 28 °C, brown to dark brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on dead bamboo in a mountain, 25 January 2017, Yong-Zhong Lu, MRC10 (MFLU 17–1111, holotype; HKAS 100784, isotype), ex-type living cultures, MFLUCC 17–1803, TBRC 8901.

Notes: Morphologically, Tubeufia bambusicola is similar to T. latispora and T. longiseta by their dense, flexuous, long setae covering the whole ascomata and fusiform, slightly curved ascospores, but can be differentiated by the size of asci and ascospores (Dai et al. 2017; Lu et al. 2017b). The asci of T. bambusicola (110–145 × 13–18 μm) are smaller than T. latispora (137–235 × 20–30 μm) but similar with T. longiseta (90–140 × 14.5–18 μm), and ascospores (50–73 × 5–7 μm) are smaller than T. latispora (68–105 × 7–10 μm) but larger than T. longiseta (38.5–55.5 × 4.5–6 μm). Our multi-gene phylogenetic result shows that T. bambusicola is a distinct species and sister to T. latispora (Fig. 55).


Tubeufia brevis Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554897; Facesoffungi number: FoF 04751; Fig. 59

Fig. 59
figure 59

Tubeufia brevis (MFLU 17–1099, holotype). a Colony on decaying wood. b–d Conidiophores. e Conidiophores with conidia. f–h Conidiogenous cells. i–m Conidia. n, o Colonies on PDA from above and below. Scale bars: a = 200 µm, b–f, h–m = 20 µm, g = 10 µm

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Holotype: MFLU 17–1099

Etymology: “brevis” referring to short conidiophores of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 30–60 μm long, 3.5–5 μm wide, pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, 12–24 μm long, 3.5–4.5 μm wide, pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 38–45 μm diam. and conidial filament 4–5 μm wide (\( \bar{x} \) = 40 × 4.5 μm, n = 50), 245–305 μm long, tightly coiled 2½–3¼ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 48 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 27 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR15 (MFLU 17–1099, holotype), ex-type living cultures, MFLUCC 17–1799, TBRC.

Notes: Tubeufia brevis is characterized by short irregular branched conidiophores with tightly helicoid conidia which become loose in water. Tubeufia brevis resembles T. dentophora in conidiophore and conidial morphology but can be recognized by its wider conidial filaments (4–5 μm vs. 2.5–3.5 μm). Our multi-gene phylogenetic result shows that T. brevis is a distinct species despite the lack of support to other species (Fig. 55).


Tubeufia brunnea Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554898; Facesoffungi number: FoF 04752; Fig. 60

Fig. 60
figure 60

Tubeufia brunnea (MFLU 17–1211, holotype). a Colony on decaying wood. b Conidiophores with attached conidium. c, d Conidiophores. e–j Conidia. k, l Colonies on PDA from above and below. m Umbonate colony surface on PDA from above. Scale bars: a = 100 µm, b–j = 20 µm

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Holotype: MFLU 17–1211

Etymology: “brunnea” referring to brown colonies and brown helicoid conidia of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, brown. Mycelium composed of partly immersed, partly superficial, subhyaline to pale brown, septate, branched hyphae, with a few of glistening conidia. Conidiophores macronematous, mononematous, cylindrical, branched, 0–1-septate, 20–30 μm long, 3.5–5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, 12–18 μm long, 2.5–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acrogenous, helicoid, rounded at tip, 35–45 μm diam. and conidial filament 7–9 μm wide in the broadest part (\( \bar{x} \) = 40 × 8 μm, n = 20), tapering to 3–4 μm wide near the ends, 170–250 μm long, tightly coiled 1½–2½ times, not becoming loose in water, indistinctly multi-septate, guttulate, hyaline when young, pale brown when aged, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, umbonate surface, edge entire, reaching 35 mm in 1 month at 28 °C, pale brown to brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 25 March 2017, Yong-Zhong Lu, CR41 (MFLU 17–1211, holotype; HKAS 100777, isotype), ex-type living culture, MFLUCC 17–2022.

Notes: Morphologically, Tubeufia brunnea can be easily recognized from other Tubeufia species by its subhyaline to pale brown colonies on natural woody substrate and conidia tapering to narrow ends. Phylogenetically, Tubeufia brunnea shares a sister relationship to T. hechiensis and T. taiwanensis with high bootstrap support and support that they are distinct species (Fig. 55).


Tubeufia chiangmaiensis Boonmee & K.D. Hyde, Fungal Diversity 68: 248 (2014)

Index Fungorum: IF 550705; Facesoffungi number: FoF 00172; Fig. 61

Fig. 61
figure 61

The asexual morph of Tubeufia chiangmaiensis (MFLU 17–1108). a Colony on decaying wood. b–f Conidiophores. g–l Conidia. m–o Conidiogenous cells. p, q Colonies on PDA from above and below. r Umbonate colony surface on PDA from above. Scale bars: a = 200 µm, b, c = 50 µm, d–l = 20 µm, m–o = 10 µm

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Type: THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on dead wood of an unidentified tree, 23 June 2011, Saranyaphat Boonmee, MFLU 11–1149 (holotype).

Known distribution: Thailand

Habitat: Terrestrial.

Saprobic on decaying wood in a mountain. Sexual morph See Boonmee et al. (2014). Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 40–105 μm long, 4–5.5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, with conspicuous denticles, 7.5–15 μm long, 3–4.5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 25–30 μm diam. and conidial filament 3–4 μm wide (\( \bar{x} \) = 28 × 3.5 μm, n = 20), 170–230 μm long, tightly coiled 2½–3½ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, obviously umbonate, with rough surface, veined and wrinkle, edge entire, reaching 18 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on decaying wood in a mountain, 25 January 2017, Yong-Zhong Lu, MRC07 (MFLU 17–1108 = HKAS 100782), living culture, MFLUCC 17–1801.

Notes: Tubeufia chiangmaiensis was introduced by Boonmee et al. (2014) based on the sexual morphology and molecular data. It was collected from Mushroom Research Center, Chiang Mai Province, Thailand. Up to date, there is no report on the asexual morph of this species. During a collecting trip around Mushroom Research Center, we collected an asexual morph taxon and it is morphologically similar to the asexual morph of Tubeufia species. Our multi-gene phylogenetic analyses show that the newly obtained isolate clustered with the ex-type strain of T. chiangmaiensis with high bootstrap support (Fig. 55). Besides, their ITS and LSU sequence data are identical and there is only one base pair nucleotide difference in TEF1α, which provides a strong evidence to indicate that they are the same species. Therefore, we linked the sexual-asexual morph for T. chiangmaiensis.


Tubeufia chlamydospora Y.Z. Lu, Boonmee & K.D. Hyde, sp. nov.

Index Fungorum: IF 554899; Facesoffungi number: FoF 04754; Fig. 62

Fig. 62
figure 62

Tubeufia chlamydospora (MFLU 17–1172, holotype). a, b Colony on decaying wood. c–f Conidia with immersed hyphae. g–p Conidia. q, r Colony on MEA from above and below. Scale bars: a, b = 100 µm, c–p = 50 µm

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Holotype: MFLU 17–1172

Etymology: “chlamydospora” referring to chlamydospores of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, chlamydosporous. Conidiophores lacking. Conidiogenous cells holoblastic, monoblastic, integrated, cylindric, apical, pale brown. Chlamydospores acrogenous, carbonaceous, friable, solitary, variable in shape, globose or subglobose, ovoid to irregular, indistinctly dictyoseptate, verrucose, 65–100 μm long, 60–90 μm wide (\( \bar{x} \) = 83 × 71 μm, n = 20), hyaline to pale brown when young, dark brown to black when matured. Some conidia formed small globose to subglobose secondary conidia (Fig. 62n, o), 8–12 μm in diam., attached to the margin of the chlamydospore, pale brown.

Culture characteristics: Conidia germinating on water agar and producing germ tubes within 24 h. Colonies growing on malt extract agar, circular, with flat surface, edge filiform, reaching 26 mm in 4 weeks at 28 °C, brown to dark brown in MEA media. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown.

Material examined: THAILAND, Krabi, Muang, Nongtalay, Khao Hang Nak, on submerged decaying wood in a freshwater stream, 16 December 2015, Saranyaphat Boonmee, HN05–2 (MFLU 17–1172, holotype), ex-type living cultures, MFLUCC 16–0223, TBRC 8896.

Notes: Morphologically, Tubeufia chlamydospora resembles Artocarpomyces paradoxus in having conidia that are variable in shape, globose or subglobose, ovoid to irregular, indistinctly dictyoseptate, verrucose, but can be distinguished by its larger conidial size (65–100 × 60–90 μm vs. 55–90 × 30–60 μm) and different conidiophore morphology as well as lack of stroma (Subramanian 1994). Tubeufia chlamydospora resembles Chlamydotubeufia huaikangplaensis and Neochlamydotubeufia khunkornensis in colony features on decaying woody substrate but can be distinguished by conidial morphology. The conidia of T. chlamydospora are acrogenous, sometimes with small globose to subglobose secondary conidia, while C. huaikangplaensis and C. khunkornensis are developed from hyphae having a pedicellate-like mycelium exist in both ends. Besides, the conidia of T. chlamydospora are vaguely dictyoseptate, while C. huaikangplaensis and C. khunkornensis have clearly dictyoseptate conidia. Phylogenetically, T. chlamydospora groups within Tubeufia and shares a sister relationship to T. machaerinae with high bootstrap support (Fig. 55). The close phylogenetic relationship between T. chlamydospora and T. machaerinae is unexpected as their morphology is remarkably different, but supported by strong molecular evidence, therefore, we introduce the new collection as a new Tubeufia species.


Tubeufia cylindrothecia (Seaver) Höhn Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 128: 562 (1919)

Index Fungorum: IF 340543; Facesoffungi number: FoF 02650

Reference specimen: MFLU 16–2547

Known distribution: Belgium, Bermuda, Brazil, Britain, China, Colombia, Costa Rica, Denmark, French Guiana, New Zealand, Spain, Thailand, USA, Venezuela.

Habitat: Aquatic.

Description: For a complete description see Luo et al. (2017).

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR03–2 (MFLU 17–1087 = HKAS 100759), living culture, MFLUCC 17–1792.

Notes: Tubeufia cylindrothecia was found as a sexual morph and frequently associated with the asexual morph referred to as Helicomyces roseus based on morphological studies (Seaver and Waterston 1940; Barr 1980; Zhao et al. 2007). Luo et al. (2017) first reported its asexual morph on submerged decaying wood collected from freshwater habitat in Yunnan Province, China. Our phylogenetic result shows that our newly obtained isolate MFLUCC 17–1792 and one unidentified isolate Tubeufia sp. (BCC 3585) (Tsui et al. 2006) are same as other T. cylindrothecia strains (Fig. 55). We also compared MFLUCC 17–1792 and BCC 3585 to other T. cylindrothecia strains and there are no nucleotide differences between them. Therefore, we identified the newly obtained isolate and Tubeufia sp. BCC 3585 as Tubeufia cylindrothecia.


Tubeufia dictyospora Y.Z. Lu, Boonmee & K.D. Hyde, sp. nov.

Index Fungorum: IF 554900; Facesoffungi number: FoF 04755; Figs. 63 and 64

Fig. 63
figure 63

Tubeufia dictyospora (MFLU 17–1114, holotype). a Colony on decaying wood. b–j Conidia. k Germinating conidium. l, m Colony on PDA from above and below. Scale bars: a = 200 µm, b–k = 50 µm

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Fig. 64
figure 64

Tubeufia dictyospora (MFLU 17–1173, paratype). a Colony on decaying wood. b Hyphae on woody substrate. c–k Conidia. Scale bars: a = 200 µm, b = 10 µm, c–k = 50 µm

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Holotype: MFLU 17–1114

Etymology: “dictyospora” referring to dictyospores of this fungus.

Known distribution: Thailand.

Habitat: Aquatic, Terrestrial.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, dictyosporous. Conidiophores lacking. Conidiogenous cells holoblastic, monoblastic, integrated, cylindric, apical, pale brown. Dictyospores acrogenous, carbonaceous, friable, solitary, variable in shape, globose to subglobose, ovoid to irregular, indistinctly dictyoseptate, verrucose, size in holotype: 95–185 μm long, 60–85 μm wide (\( \bar{x} \) = 145 × 70 μm, n = 20); size in paratype: 60–100 μm long, 60–70 (–80) μm wide (\( \bar{x} \) = 75 × 65 μm, n = 20), pale brown when young, dark brown to black when matured.

Culture characteristics: Conidia germinating on water agar and producing germ tubes within 24 h. Colonies growing on PDA, circular, with flat surface, edge filiform, reaching 35 mm in 4 weeks at 28 °C, brown to dark brown in PDA media. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown.

Material examined: THAILAND, Chiang Mai, Mae Taeng, Mushroom Research Center, on decaying wood in a mountain, 25 January 2017, Yong-Zhong Lu, MRC15 (MFLU 17–1114, holotype), ex-type living cultures, MFLUCC 17–1805, TBRC 8895. THAILAND, Krabi, Muang, Nongtalay, Khao Hang Nak, on submerged decaying wood in a freshwater stream, 16 December 2015, Saranyaphat Boonmee, HN02–3 (MFLU 17–1173, paratype), living culture, MFLUCC 16–0220.

Notes: Morphologically, Tubeufia dictyospora resembles T. chlamydospora in colony features on decaying woody substrate but can be distinguished by conidial morphology. The conidia of T. dictyospora are obviously longer than T. chlamydospora (95–185 μm vs. 65–100 μm) and lack secondary conidia. Tubeufia chlamydospora resembles Artocarpomyces paradoxus in having conidia that are variable in shape, globose to subglobose, ovoid to irregular, verrucose, and can also be distinguished by conidiophore morphology (Subramanian 1994). Phylogenetically, T. dictyospora is closely related to T. machaerinae with high bootstrap support (Fig. 55). We noted that our two newly obtained isolates of T. dictyospora were phylogenetically slightly apart from each other. Following the recommendation of Jeewon and Hyde (2016) for delimitation of new species, we looked into pair wise dissimilarities of DNA sequences and noted that there are 1, 3 and 1 base pair differences in their LSU, RPB2 and TEF1α, respectively, which may explain a close phylogenetic relatedness between them and their slight phylogenetic divergence. Although most conidia of MFLU 17–1173 are morphologically globose to subglobose and in the holotype MFLU 17–1114 they are irregular, we identified these two isolates as Tubeufia dictyospora as their ITS sequence data are identical and those few base pair differences in LSU, RPB2 and TEF1α sequence data are not enough to indicate they are different species.


Tubeufia eccentrica Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554901; Facesoffungi number: FoF 04756; Fig. 65

Fig. 65
figure 65

Tubeufia eccentrica (HKAS 97439, holotype). a, b Colony on decaying wood. c–e Conidiophores with attached conidia. f–j Conidiogenous cells. k–m Conidia. n, o Colonies on PDA from above and below. Scale bars: c–e, k–m = 50 µm, f–j = 10 µm

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Holotype: HKAS 97439

Etymology: “eccentrica” referring to conidia attached conidiogenous cells eccentrically.

Known distribution: China.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, hyaline to white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, occasionally branched, septate, 30–80 μm long, 5–6 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 20–30 μm long, 4–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, attached eccentrically and seceding schizolytically, rounded at tip, 70–80 μm diam. and conidial filament 6–8 μm wide (\( \bar{x} \) = 75 × 7 μm, n = 20), 400–570 μm long, coiled 1½–2½ times, becoming loosely coiled in water, 52–62-septate, guttulate, hyaline.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 29 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 14 May 2016, Yong-Zhong Lu, PF03 (HKAS 97439, holotype; GZAAS 16–0094, isotype), ex-type living culture, MFLUCC 17–1524 = GZCC 16–0082; Ibid., PF08–1 (GZAAS 16–0096, paratype), living culture, GZCC 16–0084; CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, JHC05–2 (GZAAS 16–0047, paratype), living culture, GZCC 16–0035; Ibid., JHC16–1 (GZAAS 16–0060, paratype), living culture, GZCC 16–0048.

Notes: Tubeufia eccentrica resembles T. inaequalis and T. guangxiense in conidiophores and conidia but can be distinguished by their conidial size. The conidial diameter of T. eccentrica (70–80 μm) is larger than T. inaequalis (45–60 μm) and T. guangxiense (45–70 μm). Phylogenetically, four isolates of T. eccentrica form a monotypic clade and share a sister relationship to T. guangxiense with good bootstrap support (Fig. 55), and support that they are distinct species.


Tubeufia fangchengensis Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554902; Facesoffungi number: FoF 04757; Fig. 66

Fig. 66
figure 66

Tubeufia fangchengensis (HKAS 97429, holotype). a Colony on decaying wood. b, c Conidiophores with attached conidia. d, e Conidiophores. f–i Conidia. j, k Colonies on PDA from above and below. Scale bars: b–i = 20 µm

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Holotype: HKAS 97429

Etymology: “fangchengensis” referring to collecting site.

Known distribution: China (Guangxi).

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 30–135 μm long, 3–5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, truncate at apex after conidial secession, 7–13 μm long, 2.5–3.5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 20–40 μm diam. and conidial filament 2.5–4 μm wide (\( \bar{x} \) = 30 × 3 μm, n = 20), 165–220 μm long, coiled 1½–2½ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 24 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 25 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, JHC14–4 (HKAS 97429, holotype; GZAAS 16–0059, isotype), ex-type living cultures MFLUCC 17–0047, GZCC 16–0047, TBRC 8897.

Notes: Tubeufia fangchengensis is morphologically similar to Tubeufia parvispora with flexuous, cylindrical, branched, pale brown conidiophores. However, T. fangchengensis can be recognized from T. parvispora by its larger-sized conidia (20–40 × 165–220 μm vs. 15–20 × 105–155 μm). Our multi-gene phylogenetic analysis supports that T. fangchengensis as a distinct Tubeufia species (Fig. 55).


Tubeufia filiformis Y.Z. Lu, Boonmee & K.D. Hyde, Mycol. Progr. 16(4): 407 (2017)

Index Fungorum: IF 818986; Facesoffungi number: FoF 02692

Type: THAILAND, Krabi, Plai Praya, Khao To, Ban Bang Thao Mae, on decaying wood in a freshwater stream, 17 December 2015, Saranyaphat Boonmee, MFLU 16–2659 (holotype).

Known distribution: Thailand.

Habitat: Aquatic.

Description: For a complete description of this taxon see Lu et al. (2017b).

Material examined: THAILAND, Krabi, Muang, Khao Khram, Ban Nong Jig, Tha Pom Klong Song Nam, on decaying wood in freshwater stream, 16 December 2015, Saranyaphat Boonmee, TP02–2 (HKAS 100727), living culture, MFLUCC 16–0236.

Notes: Our new collection is a helicosporous hyphomycete developing on decaying woody substrate, identical to Tubeufia filiformis. The newly obtained isolate clustered together with two known T. filiformis and the phylogeny confirms that they are the same species (Fig. 55).


Tubeufia guangxiensis Chaiwan, Boonmee, Y.Z. Lu & K.D. Hyde, Mycosphere 8(9): 1150 (2017)

Index Fungorum: IF 553873; Facesoffungi number: FoF 03779

Type: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Y.Z. Lu, GZAAS 16–0057 (holotype).

Known distribution: China.

Habitat: Aquatic.

Description: For a complete description of this taxon see Chaiwan et al. (2017).

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Y.Z. Lu, JHC14–3 (HKAS 97428 = GZAAS 16–0058), living cultures, MFLUCC 17–0046, GZCC 16–0046.

Notes: Our new collection is a helicosporous hyphomycete developing on the decaying woody substrate, is identical to Tubeufia guangxiensis. The newly obtained isolate clusters together with six known T. guangxiensis and phylogeny confirms that they are the same species (Fig. 55).


Tubeufia hechiensis Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554903; Facesoffungi number: FoF 04758; Fig. 67

Fig. 67
figure 67

Tubeufia hechiensis (HKAS 97443, holotype). a Colony on decaying wood. b, c Conidiophores d, e Conidiogenous cells. f–k Conidia. l, m Colonies on PDA from above and below. Scale bars: b, c, f–k = 20 µm, d, e = 10 µm

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Holotype: HKAS 97443

Etymology: “hechiensis” referring the collecting site.

Known distribution: China (Guangxi).

Habitat: Aquatic.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 50–210 μm long, 4.5–6.5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, with denticles, 12–16 μm long, 4–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, pleurogenous, helicoid, rounded at tip, 45–55 μm diam. and conidial filament 4–5 μm wide (\( \bar{x} \) = 51 × 4.7 μm, n = 20), 230–280 μm long, loosely coiled 1–2 times, becoming loosely or uncoiled in water, indistinctly multi-septate, guttulate, hyaline.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 23 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Hechi City, on submerged decaying wood in a freshwater stream, 18 May 2016, Yong-Zhong Lu, XSL05 (HKAS 97443, holotype; GZAAS 16–0084, isotype), ex-type living culture, MFLUCC 17–0052, GZCC 16–0072.

Notes: Tubeufia hechiensis is morphologically characterized by loosely coiled conidia similar to T. sympodihylospora, but can be easily distinguished by its conidiophore and conidiogenous cell morphology. Tubeufia sympodihylospora have sympodial conidiogenous cells with a truncate shape after conidial secession but T. hechiensis lacks this characteristic. Phylogenetically, T. hechiensis shares a sister relationship to T. taiwanensis (Fig. 55) and support them as distinct species. They differ in morphology of conidiophores, conidiogenous cells and conidia as well, and hence substantiate that they are different.


Tubeufia hyalospora Y.Z. Lu, Boonmee & K.D. Hyde, Fungal Diversity 80: 126 (2016)

Index Fungorum: IF 552220; Facesoffungi number: FoF 02361

Type: THAILAND, Prachuap Khiri Khan, Bang Sapan, Ron Thai, on decaying wood in flowing freshwater stream, 30 July 2015, K.D. Hyde, MFLU 16–1135 (holotype).

Known distribution: Thailand.

Habitat: Aquatic.

Description: For a complete description of this taxon see Hyde et al. (2016a).

Notes: This taxon was introduced by Hyde et al. (2016a). We observed that the sequence data deposited are of low quality and, therefore, we re-extracted its DNA from ex-type cultures (MFLUCC 15–1250) and update its sequence data in this study. The previous LSU sequence data (GenBank accession KX454179) should not be used in future phylogenetic analyses.


Tubeufia inaequalis Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554904; Facesoffungi number: FoF 04759; Fig. 68

Fig. 68
figure 68

Tubeufia inaequalis (HKAS 97440, holotype). a Colony on decaying wood. b, c Conidiophores. d, e Conidiophores with attached conidia. f–g Conidiogenous cells. h–m Conidia. n, o Colonies on PDA from above and below. Scale bars: b–e = 20 µm, f–g = 10 µm, h–m = 50 µm

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Holotype: HKAS 97440

Etymology: “inaequalis” referring to irregular conidiogenous cells of this fungus.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 33–86 μm long, 4–5.5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, irregular cylindrical, sympodial, repeatedly geniculate, truncate at apex after conidial secession, 8–17 μm long, 4–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 45–60 μm diam. and conidial filament 5.5–9 μm wide (\( \bar{x} \) = 51 × 7 μm, n = 50), 350–480 μm long, coiled 2–3½ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, obviously umbonate, with rough surface, veined and wrinkle, edge entire, reaching 15 mm in 2 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 14 May 2016, Yong-Zhong Lu, PF09–1 (HKAS 97440, holotype; GZAAS 16–0097, isotype), ex-type living culture, MFLUCC 17–0053 = GZCC 16–0085; Ibid., PF01–4 (GZAAS 16–0091, paratype), living culture, GZCC 16–0079; Ibid., PF15–2 (GZAAS 16–0099, paratype), living culture, GZCC 16–0087; THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW01–3 (MFLU 17–1129 = HKAS 100801, paratype), living culture, MFLUCC 17–1989; Ibid., TW07 (MFLU 17–1138 = HKAS 100809, paratype), living culture, MFLUCC 17–1998.

Notes: Our multi-gene phylogenetic result (Fig. 55) shows that there are five new isolates that cluster together with Helicomyces roseus (BCC 8808), which was identified by Tsui et al. (2006). Boonmee et al. (2014) renamed this strain as Tubeufia roseus in their phylogenetic tree but did not formally synonymize it. We compared the sequence data of BCC 8808 with our five newly obtained isolates and there are no differences in their ITS and LSU sequences between BCC 8808 and MFLUCC 17–1998 (No protein gene data are provided for BCC 8808). Hence, they should be the same species. Besides, we noted that in our five newly obtained isolates, three of them collected from southern China were phylogenetically apart from the other two collected from Thailand. Following the recommendations of Jeewon and Hyde (2016) for delimitation of new species, we looked into pairwise dissimilarities of DNA sequences and noted that there are indeed differences in the ribosomal ITS sequences that may explain a close phylogenetic relatedness between them and their slight phylogenetic divergence from the other isolates. There are four noticeable nucleotide differences among the 550 nucleotides analyzed between isolates (MFLUCC 17–0053, GZCC 16–0079 and GZCC 16–0087) and the other two (MFLUCC 17–1989 and MFLUCC 17–1998). Major differences are as follows: nucleotide T instead of C at position 35 and 92; nucleotide T inserted at position 103; nucleotide C lost at position 486. We also compared their LSU, RPB2 and TEF1α sequence data but there are no differences between them. Furthermore, we could not observe any morphological features separating these five isolates. Accordingly, we identify these five isolates and reappraised Helicomyces roseus (BCC 8808) as T. inaequalis.


Tubeufia krabiensis Y.Z. Lu, Boonmee & K.D. Hyde, sp. nov.

Index Fungorum: IF 554905; Facesoffungi number: FoF 04760; Fig. 69

Fig. 69
figure 69

Tubeufia krabiensis (MFLU 17–1174, holotype). a Colony on decaying wood. b Conidiophore with attached conidium. c–e Conidiophores. f, g Conidiogenous cells. h–k Conidia. l Germinating conidium. m, n Colonies on MEA from above and below. Scale bars: a = 200 µm, b–e, h–l = 20 µm, f, g = 10 µm

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Holotype: MFLU 17–1174

Etymology: “krabiensis” referring to collecting site.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, cylindrical, branched, septate, 35–116 μm long, 5–6.5 μm wide, the lower part brown and the upper part hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 8.5–21 μm long, 4–5.5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 35–45 μm diam. and conidial filament 5.5–8 μm wide (\( \bar{x} \) = 39 × 6.5 μm, n = 20), 180–260 μm long, tightly coiled 2½–3¾ times, not becoming loose in water, 27–28-septate, guttulate, hyaline.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on MEA, circular, with flat surface, edge entire, reaching 28 mm in 3 weeks at 28 °C, pale brown to brown in MEA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Krabi, Plai Praya, Khao To, Ban Bang Thao Mae, on decaying wood in flowing freshwater stream, 17 December 2015, Saranyaphat Boonmee, BTM01–3 (MFLU 17–1174, holotype; HKAS 100756, isotype), ex-type living culture, MFLUCC 16–0228.

Notes: Tubeufia krabiensis is morphologically similar to T. sympodiophora and T. mackenziei in conidia characters, but can be distinguished by conidiophore and conidial size. Tubeufia krabiensis differs from T. sympodiophora and T. mackenziei by its conidiogenous cells which appear on the end cells of conidiophores. Besides, the conidiogenous cells of T. mackenziei have characteristic denticulate protrusions while T. krabiensis is repeatedly geniculate and truncate at apex after conidial secession. Furthermore, the conidiophores of T. krabiensis are shorter but wider than T. sympodiophora (35–116 × 5–6.5 μm vs. 120–300 × 4–5 μm). The conidia of T. krabiensis (35–45 μm) are larger than T. sympodiophora (22–33 μm) and T. mackenziei (26.5–32.5 μm) (Matsushima 1993; Lu et al. 2017b). Phylogenetically, T. krabiensis shares a sister relationship to T. hyalospora with high bootstrap support (Fig. 55). Tubeufia krabiensis differs from T. hyalospora in features of conidiophores and conidiogenous cells as well as conidia (Hyde et al. 2016a). The conidiogenous cells of T. krabiensis are repeatedly geniculate and truncate at apex after conidial secession in the end cells of conidiophores, while T. hyalospora has denticulate protrusions along the whole conidiophores. The conidia of T. krabiensis are larger than T. hyalospora (35–45 × 5.5–8 μm vs. 16–33 × 3–5 μm).


Tubeufia laxispora Y.Z. Lu, Boonmee & K.D. Hyde, Mycol. Progr. 16(4): 409 (2017)

Index Fungorum: IF 818987; Facesoffungi number: FoF 02694

Type: THAILAND, Krabi, Plai Praya, Khao To, Ban Bang Thao Mae, on decaying wood in a freshwater stream, 17 December 2015, Saranyaphat Boonmee, MFLU 16–2663 (holotype).

Known distribution: Thailand

Habitat: Aquatic.

Description: For a complete description of this taxon see Lu et al. (2017b).

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 25 March 2017, Yong-Zhong Lu, CR42 (MFLU 17–1212 = HKAS 100778), living culture, MFLUCC 17–2023; THAILAND, Uttaradit, Laplae, Mae Phun, Ban Ton Klua, on decaying wood in a freshwater stream, 24 October 2015, Saranyaphat Boonmee, UTD15–6 (HKAS 100716), living culture, MFLUCC 16–0013.

Notes: Our two new collections are morphologically identical to Tubeufia laxispora introduced by Lu et al. (2017b). We noted that the newly obtained isolates cluster together with two known T. laxispora strains but with a slight phylogenetic divergence from each other (Fig. 55). Following the recommendations of Jeewon and Hyde (2016) for delimitation of new species, we looked into pairwise dissimilarities of DNA sequences, and noted that there are 2 bp (base pair), 1 bp, 8 bp differences between MFLUCC 17–2023 and the type strain MFLUCC 16–0232 in ITS, RPB2 and TEF1α, respectively; and 1 bp, 1 bp, 1 bp, 8 bp differences between MFLUCC 16–0013 and the type strain MFLUCC 16–0232 in ITS, LSU, RPB2 and TEF1α, respectively, which may explain a close phylogenetic relatedness between them and their slight phylogenetic divergence from the other isolates. However, we could not observe any morphological features to separate these isolates and those minor base pair differences are not enough to indicate that they are different species. Hence, we identify our new isolates as T. laxispora.


Tubeufia parvispora Tibpromma & K.D. Hyde, Fungal Divers. 92 (2018)

Index Fungorum: IF 555292; Facesoffungi number: FoF 04514; Fig. 70

Fig. 70
figure 70

Tubeufia parvispora (MFLU 17–1143). a Colony on decaying wood. b, c Conidiophores with attached conidia. d, e Conidiophores. f–j Conidia. k, l Colonies on PDA from above and below. m Umbonate colony surface on PDA from above. Scale bars: a = 100 µm, b–e = 20 µm, f–j = 10 µm

Full size image

Holotype: THAILAND, Krabi Province, Mueang Krabi District, on Pandanus sp., 16 December 2015, S. Tibpromma, MFLU 16–1911 (holotype).

Known distribution: Thailand.

Habitat: Aquatic, Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 25–133 μm long, 3–5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, with denticles, arising from the apex cell of conidiophores as tiny tooth-like protrusions, 8–16 μm long, 3–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 15–20 μm diam. and conidial filament 2–3 μm wide (\( \bar{x} \) = 18 × 2.5 μm, n = 20), 105–155 μm long, tightly coiled 2½–3½ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, obviously umbonate, with rough surface, veined and wrinkle, edge entire, reaching 26 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW12 (MFLU 17–1143 = HKAS 100814), living cultures, MFLUCC 17–2003, TBRC; Ibid., TW03–3 (MFLU 17–1132 = HKAS 100803), living culture, MFLUCC 17–1992; Ibid., on decaying wood in a mountain, 26 April 2017, Yong-Zhong Lu, TM02 (MFLU 17–1149 = HKAS 100820), living culture, MFLUCC 17–2009.

Notes: Tubeufia parvispora was introduced by Tibpromma et al. (2018). In this study, we report three new collections of Tubeufia parvispora from a freshwater habitat and is the first record of T. parvispora from aquatic habitats. Tubeufia parvispora is morphologically similar to Tubeufia rubra in having flexuous, branched conidiophores with hyaline helicoid conidia becoming loosely coiled in water, but can be recognized by its conidiophores. The conidiophores of T. rubra are repeatedly geniculate and conidiogenous cells truncate at apex after conidial secession, whereas T. parvispora is characterized by tooth-like conidiogenous protrusions arising from the apex cell of conidiophores. Besides, T. parvispora differs from T. rubra in having smaller conidia (15–20 × 105–155 μm vs. 36–49 × 230–370 μm). Phylogenetically, the three newly obtained isolates formed a cluster with high bootstrap support (Fig. 55) and support that it is a distinct species.


Tubeufia roseohelicospora Y.Z. Lu, Boonmee & K.D. Hyde, Fungal Diversity 80: 128 (2016)

Index Fungorum: IF 552222; Facesoffungi number: FoF 02362; Figs. 71 and 72

Fig. 71
figure 71

Tubeufia roseohelicospora (MFLU 17–1097). a Colony on decaying wood. b–d Conidiophores with attached conidia. e Conidiophores with attached conidium. f–k Conidia. l, m Colonies on PDA from above and below. Scale bars: a = 200 µm, b–k = 50 µm

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Fig. 72
figure 72

Tubeufia roseohelicospora (MFLU 17–1176). a Colony on decaying wood. b–d Conidiophores with attached conidia. e–g Conidiophores. h–k Conidia. Scale bars: a = 200 µm, b–g = 20 µm, h–k = 50 µm

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Holotype: MFLU 16–1133

Known distribution: Thailand

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, hyaline to white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with masses of crowded, glistening conidia. In specimen MFLU 17–1097: Conidiophores macronematous, mononematous, erect, cylindrical, mostly unbranched, septate, 45–85 μm long, 6–7 μm wide, brown, smooth-walled. Conidiogenous cells holoblastic, monoblastic, integrated, sympodial, terminal, cylindrical, with denticle, arising from the apex of conidiophore as tiny tooth-like protrusion, 10–20 μm long, 5–6 μm wide, brown, smooth-walled. Conidia solitary, acrogenous, helicoid, attached eccentrically and seceding schizolytically, rounded at tip, 70–90 μm diam. and conidial filament 5–6 μm wide (\( \bar{x} \) = 80 × 5.5 μm, n = 20), 380–480 μm long, loosely coiled 1½–2 times, becoming loosely coiled or uncoiled in water, 45–55-septate, guttulate, hyaline. In specimen MFLU 17–1176: Conidiophores macronematous, mononematous, erect, flexuous, cylindrical, unbranched or branched, septate, 45–70 μm long, 4.5–5.5 μm wide, pale brown to brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 10–20 μm long, 4.5–5.5 μm wide, pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, attached eccentrically and seceding schizolytically, rounded at tip, 60–80 μm diam. and conidial filament 4.5–6 μm wide (\( \bar{x} \) = 70 × 5.5 μm, n = 20), 350–500 μm long, tightly coiled 2–3½ times, becoming loosely coiled in water, 45–50-septate, guttulate, hyaline.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 22 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 31 December 2016, Yong-Zhong Lu, CR13 (MFLU 17–1097 = HKAS 100767), living culture, MFLUCC 17–1797; THAILAND, Krabi, Plai Praya, Khao To, Ban Bang Thao Mae, on submerged decaying wood in a freshwater stream, 17 December 2015, Saranyaphat Boonmee, BTM02 (MFLU 17–1176 = HKAS 100758), living culture, MFLUCC 16–0230.

Notes: Although our two new isolates differ in conidiophore and conidial shape (showed in Figs. 71, 72), we believe that they are conspecific because their ITS, LSU, RPB2 and TEF1α sequence data are identical. Phylogenetically, these two isolates share a sister relationship to T. roseohelicospora MFLUCC 15–1247 and support them as conspecific (Fig. 55). We compare sequence data and found that there is no difference in their ITS sequence data, and their slightly phylogenetic divergence came from 7 bp (base pair) and 1 bp differences in LSU and RPB2 sequence data, respectively. Therefore, we identified our isolates as T. roseohelicospora. It is necessary to point out that three isolates of T. roseohelicospora are slightly different in their conidiophores and conidia characters (Figs. 71, 72 and Hyde et al. 2016a), and possibly suggest that this species might be genetically diverse.


Tubeufia rubra Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554907; Facesoffungi number: FoF 04762; Fig. 73

Fig. 73
figure 73

Tubeufia rubra (HKAS 7438, holotype). a, b Colony on decaying wood. c Conidiophores with attached conidium. d, e Conidiogenous cells. f–k Conidia. l, m Colonies on PDA from above and below. n Umbonate colony surface on PDA from above. Scale bars: c = 50 µm, d, e = 10 µm, f–k = 20 µm

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Holotype: HKAS 7438

Etymology: “rubra” referring to the red brown colonies on woody substrate.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substrate superficial, effuse, gregarious, hyaline on fresh woody substrate, becoming red brown when dried. Mycelium composed of partly immersed, partly superficial, hyaline to dark brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 50–150 μm long, 4.5–6 μm wide, the lower part dark brown and the upper part hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 10–19 μm long, 3–4 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 35–50 μm diam. and conidial filament 3–5 μm wide (\( \bar{x} \) = 45 × 4.5 μm, n = 20), 230–370 μm long, tightly coiled 2–3½ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline to pale brown, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, obviously umbonate, with rough surface, veined and wrinkle, edge entire, reaching 16 mm in 2 weeks at 28 °C, brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 14 May 2016, Yong-Zhong Lu, PF02–2 (HKAS 7438, holotype; GZAAS 16–0093, isotype), ex-type living culture, GZCC 16–0081; Ibid., PF06 (GZAAS 16–0095, paratype), living culture, GZCC 16–0083.

Notes: Tubeufia rubra is morphologically distinct from other helicosporous hyphomycetes by its colonies on natural substrate which are hyaline first, and becoming red brown when dried. Its conidia are similar to T. chiangmaiensis but can be distinguished by conidiophore morphology. Phylogenetically, our two isolates of T. rubra formed one clade and shares a sister relationship to T. inaequalis with high bootstrap support (Fig. 55), and support that they are distinct species.


Tubeufia sessilis Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554908; Facesoffungi number: FoF 04763; Fig. 74

Fig. 74
figure 74

Tubeufia sessilis (MFLU 17–1165, holotype). a, b Superficial ascomata on substrate. Note ascomata surrounded by black setae. c Ascoma. d Peridium. e, f Setae. g–j Asci. k–p Ascospores. q, r Colonies on PDA from above and below. Scale bars: a, b = 500 µm, c, e, f = 100 µm, d, k–p = 20 µm, g–j = 50 µm

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Holotype: MFLU 17–1165

Etymology: “sessilis” referring to sessile asci of this fungus.

Known distribution: Thailand.

Habitat: Terrestrial.

Saprobic on decaying wood in a mountain Sexual morph Ascomata 195–305 μm high, 145–195 μm diam., superficial, gregarious, ellipsoidal, subglobose, setose, coriaceous, with a central ostiole, dark brown to black. Ostiole single, central. Setae 230–360 × 3.5–5 μm (\( \bar{x} \) = 290 × 4 μm, n = 20), dense, flexuous, covering the whole ascoma, unbranched, rounded at apical end, septate, dark brown. Peridium 28–41 μm wide, comprising dark brown cells of textura angularis, with innermost part comprising thin layers of hyaline to pale brown cells of textura subprismatica. Hamathecium comprising numerous filiform, septate, branched, hyaline pseudoparaphyses. Asci 150–180 × 19–25 μm (\( \bar{x} \) = 165 × 22 μm, n = 20), 8-spored, bitunicate, cylindrical, rounded the apex, with an ocular chamber, sessile, hyaline, smooth-walled. Ascospores 70–85 × 5–7 μm (\( \bar{x} \) = 77 × 6 μm, n = 50), biseriate, fusiform, cylindrical, slightly curved, tapering towards rounded ends, up to 13-septate, guttulate, hyaline, smooth-walled. Asexual morph Undetermined.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing on PDA, circular, with flat surface, edge undulate, reaching 19 mm in 2 weeks at 28 °C, pale brown to brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, Saprobic on decaying wood in a mountain, 28 November 2015, Saranyaphat Boonmee and Yong-Zhong Lu, TUB01 (MFLU 17–1165, holotype; HKAS 100721, isotype), ex-type living cultures, MFLUCC 16–0021, TBRC.

Notes: Tubeufia sessilis is morphologically similar to T. bambusicola, T. latispora and T. longiseta in their dense, flexuous and long setae covering the whole ascomata, but can be differentiated based on size of asci and ascospores (Dai et al. 2017; Lu et al. 2017b). The asci of T. sessilis (150–180 μm × 19–25 μm) are larger than T. bambusicola (110–145 μm × 13–18 μm) and T. longiseta (90–140 μm × 14.5–18 μm) but similar to T. latispora (137–235 μm × 20–30 μm), and ascospores (70–85 μm × 5–7 μm) larger than T. bambusicola (50–73 μm × 5–7 μm) and T. longiseta (38.5–55.5 μm × 4.5–6 μm) but smaller than T. latispora (68–105 μm × 7–10 μm). Tubeufia sessilis shares a sister relationship with T. longiseta and the phylogeny supports that they are distinct species (Fig. 55).


Tubeufia sympodihylospora Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554909; Facesoffungi number: FoF 04764; Fig. 75

Fig. 75
figure 75

Tubeufia sympodihylospora (HKAS 97427, holotype). a, b Colonies on decaying wood. c–f Conidiophores. g–l Conidia. m, n Colony on PDA from above and below. Scale bars: c–f = 20 µm, g–l = 50 µm

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Holotype: HKAS 97427

Etymology: “sympodi-” referring to sympodial conidiogenous cells of this fungus; “hylospora” referring to hyaline helicoid conidia.

Known distribution: China.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 40–90 μm long, 5–7 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 8–16 μm long, 5–6 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 55–70 μm diam. and conidial filament 5–7 μm wide (\( \bar{x} \) = 62 × 6 μm, n = 20), 310–370 μm long, loosely coiled 1¾–2¼ times, becoming loose in water, indistinctly multi-septate, guttulate, hyaline.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 28 mm in 4 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, JHC12–1 (HKAS 97427, holotype; GZAAS 16–0055, isotype), ex-type living cultures, MFLUCC 17–0044, GZCC 16–0043, TBRC 8893; Ibid., JHC16–2 (GZAAS 16–0061, paratype), living culture, GZCC 16–0049; Ibid., JHC17–3 (GZAAS 16–0063, paratype), living culture, GZCC 16–0051.

Notes: Morphologically, Tubeufia sympodihylospora is similar to T. sympodiophora in having holoblastic, sympodial conidiogenous cells with a truncate apex after conidial secession but can be easily recognized by its loosely helicoid conidia. Besides, T. sympodihylospora differs from T. sympodiophora in having shorter conidiophores (40–90 μm vs. 120–300 μm). Phylogenetically, T. sympodihylospora shares a sister relationship to Tubeufia xylophila with high bootstrap support (Fig. 55), and can be considered as distinct species.


Tubeufia sympodilaxispora Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554910; Facesoffungi number: FoF 04765; Fig. 76

Fig. 76
figure 76

Tubeufia sympodilaxispora (HKAS 97430, holotype). a Colony on decaying wood. b, c Conidiophores. d, e Conidiophores with attached conidia. f, g Conidiogenous cells. h–l Conidia. m, n Colonies on PDA from above and below. Scale bars: b, e = 20 µm, c, f, g = 10 µm, d, h–l = 50 µm

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Holotype: HKAS 97430

Etymology: “sympodi-” referring to sympodial conidiogenous cells of this fungus; “laxispora” referring to loosely helicoid conidia.

Known distribution: China (Guangxi).

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 25–45 μm long, 3–5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 9–17 μm long, 3–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 45–70 μm diam. and conidial filament 5–8 μm wide (\( \bar{x} \) = 60 × 6.5 μm, n = 20), 270–455 μm long, loosely coiled 1¼–1¾ times, becoming loosely coiled or fully uncoiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 24 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 21 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, JHC21–2 (HKAS 97430, holotype; GZAAS 16–0064, isotype), ex-type living culture, MFLUCC 17–0048, GZCC 16–0052; Ibid., JHC 24 (GZAAS 16–0070, paratype), living culture, GZCC 16–0058.

Notes: Morphologically, Tubeufia sympodilaxispora is similar to T. sympodihylospora in conidiogenous cells and conidia, but can be recognized by its shorter and narrower conidiophores (25–45 × 3–5 μm vs. 40–90 × 5–7 μm). Our two newly obtained isolates clustered together with two unidentified Tubeufia strains (Tubeufia sp. BCC 3580 and Tubeufia sp. MLTS 119). We could not compare their morphology because the latter two lack morphological information (Kodsueb et al. 2006), but our phylogenetic result indicates that they are the same species. We compare sequence data and found that there are only two noticeable nucleotide differences in LSU between the ex-type strain MFLUCC 17–0048 and Tubeufia sp. BCC 3580, and no difference between MFLUCC 17–0048 and Tubeufia sp. MLTS 119 (both BCC 3580 and MLTS 119 have only LSU sequence data), which also indicate that they are conspecific. Therefore, we introduce these four isolates as Tubeufia sympodilaxispora sp. nov.


Tubeufia taiwanensis Y.Z. Lu & K.D. Hyde, sp. nov.

Index Fungorum: IF 554911; Facesoffungi number: FoF 04817

Type: CHINA, Taiwan, Chiayi County, Juchi Township, on decaying wood submerged in a freshwater stream, 5 February 2017, Chang-Hsin Kuo, NCYU-K4-1, holotype, deposited at National Chiayi University, Chiayi County, Taiwan; ex-type living culture BCRC FU30844.

Etymology: “taiwanensis” referring to the collecting site.

Known distribution: China (Taiwan).

Habitat: Aquatic.

Description: For a complete description of this taxon see Kuo and Goh (2018b, as Helicomyces torquatus).

Notes: This collection was introduced as Helicomyces torquatus by Kuo and Goh (2018b) with descriptions and illustrations and sequence data. However, its morphology differs from previously described Helicomyces torquatus in having abundant stalked sclerotia and each conidium has attached several secondary conidia (Kuo and Goh 2018b). In addition, our phylogenetic result shows that the isolate BCRC FU30844 groups within Tubeufia and sister to T. hechiensis (Fig. 55), which indicates that it should be treated as a Tubeufia species. Its morphology differs from Tubeufia hechiensis in conidiophores and conidia. We also compare their sequence data and there are nine base pair differences among the 543 nucleotides ITS sequences between the isolate BCRC FU30844 (only ITS sequence data is available) and T. hechiensis (MFLUCC 17–0052), which also support that they are distinct species. Therefore, we introduce Tubeufia taiwanensis sp. nov. in this study.


Tubeufia tectonae Doilom & K.D. Hyde, Fungal Diversity 82: 150 (2016)

Index Fungorum: IF 551973; Facesoffungi number: FoF 01867; Fig. 77

Fig. 77
figure 77

Tubeufia tectonae (HKAS 100797). a, b Superficial ascomata on substrate. c, d Ascoma. e Peridium. f–i Asci. j–l Ascospores. m, n Colonies on PDA from above and below. o Umbonate colony surface on PDA from above. Scale bars: a–d = 200 µm, e–l = 50 µm

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Holotype: MFLU 15–3423

Known distribution: Thailand

Habitat: Aquatic, Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Ascomata 160–400 μm high × 140–360 μm diam., superficial, seated on a subiculum, solitary, oval, cream-white to yellowish when young, brownish to brown when matured, apex rounded, base narrow, brown to dark brown, coriaceous, collapsing when dry, compressed subiculum hyphae, 4–6 μm wide, partially branched, septate, dark brown. Peridium 39–52 μm wide, comprising light brown cells of textura angularis, and inwardly small, subhyaline cells of textura prismatica. Hamathecium comprising numerous, 1–2 μm wide, filiform, septate, branched pseudoparaphyses. Asci 110–210 × 12–17 μm (\( \bar{x} \) = 157 × 14 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical, short pedicellate, apically rounded, with an ocular chamber. Ascospores 100–155 (–188) × 4–6 μm (\( \bar{x} \) = 125 × 4.5 μm, n = 50), fasciculate, broadly filiform, cylindrical to long subfusiform, elongate, ends rounded, indistinctly multi-septate, not constricted at septa, hyaline, verrucose, guttulate. Asexual morph Undetermined.

Culture characteristics: Ascospores germinating on water agar and germ tubes produced from ascospores within 12 h. Colonies growing on PDA, irregular, with umbonate surface, edge undulate, reaching 21 mm in 2 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on decaying wood in a dry stream, 27 April 2017, Yong-Zhong Lu, TD11 (HKAS 100797), living culture, MFLUCC 17–1985; THAILAND, Krabi, Muang, Khao Khram, Ban Nong Jig, Tha Pom Klong Song Nam, on decaying wood in freshwater stream, 16 December 2015, Saranyaphat Boonmee, TP02–1 (MFLU 17–1182 = HKAS 100726), living culture, MFLUCC 16–0235.

Notes: Morphologically, our two new isolates are similar to Tubeufia javanica in having superficial cream-white to brownish oval ascomata and cylindrical asci with eight fusiform to filiform ascospores but can be distinguished by its wider peridium (39–52 vs. 15–25 μm). Phylogenetically, our isolates clustered together with T. tectonae (Fig. 55) and the phylogenetic result shows that they should be the same species. We also compare their sequence data and there are only five base pair differences in TEF1α and no differences in ITS and LSU sequence data, which also support that they are the same species. As T. tectonae was introduced as an asexual morph by Doilom et al. (2017), we linked the sexual-asexual morph for T. tectonae and this is the first time that T. tectonae has been reported from freshwater habitat.


Tubeufia tratensis Y.Z. Lu, J.C. Kang & K.D. Hyde, sp. nov.

Index Fungorum: IF 554912; Facesoffungi number: FoF 04818; Fig. 78

Fig. 78
figure 78

Tubeufia tratensis (MFLU 17–1133, holotype). a Colony on decaying wood. b–f Conidiophores. g–i Conidiogenous cells. j–n Conidia. o, p Colonies on PDA from above and below. q Umbonate colony surface on PDA from above. Scale bars: a = 100 µm, b–f, j–n = 50 µm, g–i = 20 µm

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Holotype: MFLU 17–1133

Etymology: “tratensis” referring to collecting site “Trat”.

Known distribution: Thailand.

Habitat: Aquatic.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 50–110 μm long, 4–5.5 μm wide, the lower part dark brown and the upper part hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, truncate at apex after conidial secession, 12–17 μm long, 4–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 40–50 μm diam. and conidial filament 4–5 μm wide (\( \bar{x} \) = 46 × 4.5 μm, n = 20), 260–305 μm long, coiled 2½–3¼ times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, obviously umbonate, with rough surface, veined and wrinkle, edge entire, reaching 11 mm in 1 week at 28 °C, dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: THAILAND, Trat, Amphoe Ko Chang, Yuttha Navi Ko Chang Memorial, on submerged decaying wood in a freshwater stream, 27 April 2017, Yong-Zhong Lu, TW03–4 (MFLU 17–1133, holotype; HKAS 100804, isotype), ex-type living cultures, MFLUCC 17–1993, TBRC 8894.

Notes: Tubeufia tratensis is morphologically similar to T. abundata in conidiophores which are flexuous, cylindrical, branched, the lower part dark brown and the upper part hyaline to pale brown. However, T. tratensis differs from T. abundata by its larger-sized conidia (40–50 × 260–305 μm vs. 27–38 × 180–210 μm). Tubeufia tratensis grouped within Tubeufia species but constitutes an independent lineage with high bootstrap support (Fig. 55) and phylogenetic result supports it as a distinct species in the genus.

New combinations of Tubeufia


Tubeufia dentophora (G.Z. Zhao, Xing Z. Liu & W.P. Wu) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium dentophorum G.Z. Zhao, Xing Z. Liu & W.P. Wu, Fungal Diversity 26(2): 358 (2007)

Index Fungorum: IF 554913; Facesoffungi number: FoF 04819

Type: CHINA, Guangdong Province, Lufu Mountain, on dead branches of unidentified plant, 15 October 1998, Wenping Wu, WU2013b.

Known distribution: China (Guangdong).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Zhao et al. (2007, as Helicosporium dentophorum).

Notes: This taxon was introduced as Helicosporium dentophorum by Zhao et al. (2007) based on its short conidiophores arising laterally from the creeping hyphae and its denticulate conidiogenous cells similar to other known Helicosporium species. However, we compared its morphology with our new collections and other known Helicosporium species, in that its morphology does not correspond to the generic concept of Helicosporium but instead resembles Tubeufia brevis in conidiophores and conidia, and can be recognized by its shorter conidiophores (up to 35 μm vs. 30–60 μm) and narrower conidia (2.5–3.5 μm vs. 4–5 μm). Therefore, we synonymize it as Tubeufia dentophora.


Tubeufia geniculata (C.H. Kuo & Goh) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicomyces geniculatus C.H. Kuo & Goh, Mycoscience (2018), https://doi.org/10.1016/j.myc.2018.04.002

Index Fungorum: IF 554914; Facesoffungi number: FoF 04820

Type: CHINA, Taiwan, Chiayi County, Juchi Township, on decaying wood submerged in a freshwater stream, 5 February 2017, Chang-Hsin Kuo, NCYU-U2-1 (TNM F31100, holotype).

Known distribution: China (Taiwan).

Habitat: Aquatic.

Description: For a complete description of this taxon see Kuo and Goh (2018b, as Helicomyces geniculatus).

Notes: This species was introduced as Helicomyces geniculatus by Kuo and Goh (2018b) based on phylogeny and morphology. However, we compare its morphology with our new collections and other known Helicomyces species, and its morphology does not correspond to the generic concept of Helicomyces but fits well into Tubeufia. Furthermore, our phylogenetic result shows that two isolates of H. geniculatus (BCRC FU30849 and NCYU U2-1B) cluster within Tubeufia and share a sister relationship to Tubeufia abundata with good bootstrap support (Fig. 55), and phylogeny support that they are distinct species. Therefore, we synonymize it under Tubeufia as T. geniculata.


Tubeufia lilliputea (Moore) Y.Z. Lu & K.D. Hyde comb. nov.

≡ Helicomyces lilliputeus R.T. Moore, Mycologia 49: 583 (1957)

Index Fungorum: IF 554915; Facesoffungi number: FoF 04821

Type: No type specimens are available for this species.

Possible distribution: Australia, China (Hebei, Guangdong), India, Japan, USA (Hawaii).

Habitat: Terrestrial.

Description: For a complete description of this taxon see Moore (1957), Goos (1985) and Zhao et al. (2007).

Notes: This species was introduced as Helicomyces lilliputeus by Moore (1957). Rao and Rao (1964) reported a new record of H. lilliputeus and gave more detailed descriptions. Goos (1985) mentioned that the type specimen of H. lilliputeus could not be located at NYBG where Moore (1957) had deposited. Tsui et al. (2006) provided ITS and LSU sequence data for H. lilliputeus (NBRC 32664). Zhao et al. (2007) reported new records of H. lilliputeus from China. Boonmee et al. (2014) indicated that H. lilliputeus (NBRC 32664) clustered within Tubeufia and they renamed it as Tubeufia lilliputea but did not synonymize it. Thereafter, many studies followed Boonmee’s treatment and named this taxon as T. lilliputeus in phylogenetic studies (Hyde et al. 2016a; Chaiwan et al. 2017; Lu et al. 2017b; Luo et al. 2017). Our phylogenetic results also show that H. lilliputeus NBRC 32664 clustered within Tubeufia with high bootstrap support (Fig. 55). We compared its morphology described by Moore (1957), Rao and Rao (1964), Goos (1985) and Zhao et al. (2007), to our new isolates and other known helicosporous species. Its morphology fits within the generic concept of Tubeufia which is also similar to Helicomyces species. However, molecular data provided strong evidence to indicate that this taxon should be transferred to Tubeufia and therefore, we synonymized H. lilliputeus under Tubeufia lilliputea.


Tubeufia machaerinae (Goos) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicoma machaerinae Goos, Mycologia 72(3): 597 (1980)

Index Fungorum: IF 554916; Facesoffungi number: FoF 04766; Fig. 79

Fig. 79
figure 79

Tubeufia machaerinae (HKAS 97434, reference specimen). a Colony on decaying wood. b Conidia with immersed hyphae. c Hyphae. d–g Conidia. h, i Colony on PDA from above and below. Scale bars: b–g = 20 µm

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Type: USA, Hawaii, Oahu, on dead and living leaves of Machaerinae angustigoliis, 7 June 1977, R.D. Goos, H-364 (BPI 71910, holotype).

Known distribution: China (Guangxi), USA (Hawaii).

Habitat: Aquatic, Terrestrial.

Saprobic on decaying wood in terrestrial habitat on a mountain. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, inconspicuous, hyaline to light pink. Mycelium composed of partly immersed, partly superficial, hyaline, septate, branched hyphae, 2–3 μm wide, with masses of crowded, glistening conidia. Conidiophores lacking. Conidiogenous cells holoblastic, monoblastic, bearing lateral denticles from creeping hyphae, truncate at apex after conidial secession, hyaline, smooth-walled, 2–3 μm wide. Conidia solitary, acrogenous, helicoid, rounded at tip, 30–40 μm diam. and conidial filament 7–7.5 μm wide in the broadest part (\( \bar{x} \) = 34 × 7.2 μm, n = 20), tapering to 3–4 μm wide at the truncate base, 160–190 μm long, 28–35-septate, constricted at the septa, tightly coiled 2–2¾ times, will not becoming loosely in water, guttulate, hyaline, smooth-walled.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 29 mm in 3 weeks at 28 °C, brown to dark brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Hechi City, Mulun National Nature Reserve, on decaying wood in terrestrial habitat on a mountain, 19 May 2016, Yong-Zhong Lu, ML03–2 (HKAS 97434, reference specimen designated here; GZAAS 16–0073), living cultures, MFLUCC 17–0055, GZCC 16–0061.

Notes: Our new collection morphologically fits well into Helicoma machaerinae (Goos 1980). Their conidia and conidiogenous cells are identical, and both do not have conidiophores. Only one different character recognized is that the number of conidial septa (31–36 vs. 18–21). This characteristic alone is not enough to differentiate them as many helicosporous species have different number of conidial septa in younger and older stages. Hence, we identify our new collection as H. machaerinae. All Helicoma species have well developed conidiophores but this taxon lacks this character, and the morphology of conidiogenous cells does not fit into the generic concept of Helicoma. Hence, we consider that this taxon does not belong to Helicoma species. Furthermore, multi-gene phylogenetic result shows that our isolate groups within Tubeufia with high bootstrap support (Fig. 55). Therefore, we synonymize it under Tubeufia machaerinae. As the holotype of this fungus is available but lacks molecular data, we designate our new specimen HKAS 97434 as a reference specimen.


Tubeufia sympodiophora (Matsush.) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicoma sympodiophorum Matsush. [as ‘sympodiophora’], Matsush. Mycol. Mem. 7: 52 (1993)

Index Fungorum: IF 554917; Facesoffungi number: FoF 04822

Type: PERU, Loreto, decaying palm, Manu, Madre de Dios, 1990, MFC-0P317.

Possible distribution: China, Peru.

Habitat: Aquatic, Terrestrial.

Description: For a complete description of this taxon see Matsushima (1993).

Notes: This taxon was introduced as Helicoma sympodiophorum by Matsushima (1993). Lu et al. (2000) reported a new record of H. sympodiophorum from Hong Kong. In this study, we synonymize H. sympodiophorum under Tubeufia sympodiophora based on its morphological resemblance to T. krabiensis, T. mackenziei (Lu et al. 2017b) and T. sympodihylospora, which were confirmed with DNA sequence data. Tubeufia sympodiophora is similar to T. krabiensis and T. mackenziei in conidial characters but can be distinguished by its conidiophores with sympodial conidiogenous cells. Besides, T. sympodiophora differs from T. mackenziei in having longer conidiophores (120–300 vs. 60–102 μm) and wider conidial filaments (6–8 vs. 4.6–6.5 μm), and differs from T. krabiensis in longer conidiophores (120–300 vs. 35–116 μm) and smaller conidial diameter (22–33 vs. 30–45 μm). Tubeufia sympodiophora is similar to T. sympodihylospora in conidiophores with sympodial conidiogenous cells but can be recognized by its conidial morphology. We also compare Tubeufia sympodiophora to Helicoma species but its morphology does not correspond to the generic concept of Helicoma.


Tubeufia xylophila (P.N. Singh & S.K. Singh) Y.Z. Lu & K.D. Hyde, comb. nov.

≡ Helicosporium xylophilum P.N. Singh & S.K. Singh [as ‘xylophilous’], Current Research in Environmental & Applied Mycology 6(4): 251 (2016)

Index Fungorum: IF 554918; Facesoffungi number: FoF 04767; Fig. 80

Fig. 80
figure 80

Tubeufia xylophila (HKAS 97422, reference specimen). a Colony on decaying wood. b Conidiophore with attached conidium. c–e Conidiophores. f, g Colonies on PDA from above and below. h–j Conidia. Scale bars: b, c, h–j = 20 µm, d, e = 10 µm

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Type: INDIA, Maharashtra, Pune, Agharkar Research Institute campus, on unidentified dead wood, 28 April 2015, coll. P.N. Singh, AMH 9744 (holotype), PNSARI 15 (isotype).

Known distribution: China (Guangxi), India.

Habitat: Aquatic, Terrestrial.

Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, unbranched, septate, 25–75 μm long, 4.5–5.5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 10–21 μm long, 4–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 30–40 μm diam. and conidial filament 3–5.5 μm wide (\( \bar{x} \) = 36 × 4.5 μm, n = 20), 185–295 μm long, coiled 2½–3 times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline.

Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 20 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.

Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, JHC03–1 (HKAS 97422, reference specimen designated here; GZAAS 16–0044), living cultures, MFLUCC 17–1520 = GZCC 16–0032; Ibid., JHC07–3 (GZAAS 16–0050), living culture, GZCC 16–0038.

Notes: Our two collections morphologically resemble Helicosporium xylophilous, indroduced by Singh and Singh (2016) and therefore, we confirmed them as the same species. However, its morphology does not tally with those of Helicosporium but fits into Tubeufia. This taxon resembles Tubeufia cylindrothecia in conidiophore and conidial morphology but can be distinguished by its mono- to polyblastic, intercalary or terminal conidiogenous cells while T. cylindrothecia have unbranched conidiophores and monoblastic, terminal conidiogenous cells (Luo et al. 2017). Phylogentically, our two isolates share a sister relationship to T. sympodihylospora with high bootstrap support (Fig. 55) and, therefore, we synonymize this taxon as Tubeufia xylophila. As the holotype of this fungus is available but lacks molecular data, we designate our new collection HKAS 97422 as a reference specimen.

Other accepted Tubeufia species


Tubeufia acaciae Tilak, S.B. Kale & S.V.S. Kale, Sydowia 23(1–6): 11 (1970) [1969]

Index Fungorum: IF 325088

Known distribution: India.

Habitat: Terrestrial.

Notes: This taxon was introduced by Tilak and Kale (1969) based on morphology.


Tubeufia aciculospora Katum. & Y. Harada, Trans. Mycol. Soc. Japan 20(4): 423 (1979)

Index Fungorum: IF 124492

Known distribution: Japan.

Habitat: Terrestrial.

Notes: This taxon was introduced by Katsumoto and Harada (1979) based on morphology.


Tubeufia aurantiella (Penz. & Sacc.) Rossman, Mycotaxon 8(2): 489 (1979)

≡ Calonectria aurantiella Penz. & Sacc., Malpighia 11(11–12): 515 (1898) [1897]

Index Fungorum: IF 325090

Possible distribution: Brazil, Costa Rica, Indonesia, New Zealand.

Habitat: Terrestrial.

Notes: This taxon was introduced by Rossman (1979) based on morphology.


Tubeufia brevispina (M.E. Barr & Rogerson) J.L. Crane, Shearer & M.E. Barr, Can. J. Bot. 76(4): 611 (1998)

≡ Acanthostigmella brevispina M.E. Barr & Rogerson, Mycotaxon 17: 247 (1983)

Index Fungorum: IF 446352

Known distribution: USA (New York).

Habitat: Terrestrial.

Notes: This taxon was introduced as Acanthostigmella brevispina by Barr and Rogerson (1983). Crane et al. (1998) synonymized it under Tubeufia brevispina based on morphology.


Tubeufia claspisphaeria Kodsueb, Mycologia 96(3): 668 (2004)

Index Fungorum: IF 488559

Known distribution: China (Hong Kong).

Habitat: Aquatic.

Notes: This taxon was introduced by Kodsueb et al. (2004) based on morphology.


Tubeufia dactylariae H.S. Chang, Bot. Bull. Acad. sin., Taipei 44(3): 253 (2003)

Index Fungorum: IF 484155

Known distribution: China (Taiwan).

Habitat: Terrestrial.

Notes: This taxon was introduced by Chang (2003) based on morphology.


Tubeufia eugeniae (Subhedar & V.G. Rao) A. Pande, Ascomycetes of Peninsular India (Jodhpur): 172 (2008)

≡ Thaxteriella eugeniae Subhedar & V.G. Rao, Indian J. Mycol. Plant Path. 15(2): 184 (1986) [1985]

Index Fungorum: IF 538032

Known distribution: India.

Habitat: Terrestrial.

Notes: This taxon was introduced as Thaxteriella eugeniae by Subhedar and Rao (1986). Pande (2008) synonymized it under Tubeufia eugeniae based on morphology.


Tubeufia garugae (C. Ramesh) A. Pande [as ‘garugii’], Ascomycetes of Peninsular India (Jodhpur): 173 (2008)

≡ Thaxteriella garugae C. Ramesh [as ‘garugii’], Indian Botanical Reporter 7(1–2): 55 (1988)

Index Fungorum: IF 538019

Known distribution: India.

Habitat: Terrestrial.

Notes: This taxon was introduced as Thaxteriella garugae by Ramesh (1988). Pande (2008) synonymized it under Tubeufia garugae based on morphology.


Tubeufia javanica Penz. & Sacc., Malpighia 11(11-12): 517 (1898) [1897]

Index Fungorum: IF 244755

Possible distribution: Colombia, Indonesia, Peru, Thailand.

Habitat: Terrestrial.

Notes: Tubeufia javanica is the type species of Tubeufia. Boonmee et al. (2014) first reported its phylogenetic relationship and designated the specimen MFLU 13–0371 as an epitype.


Tubeufia latispora Y.Z. Lu, Boonmee & K.D. Hyde, Mycol. Progr. 16(4): 409 (2017)

Index Fungorum: IF 818985

Known distribution: Thailand.

Habitat: Aquatic.

Notes: Tubeufia latispora was introduced by Lu et al. (2017b) based on phylogeny and morphological evidence.


Tubeufia longiseta D.Q. Dai & K.D. Hyde, Fungal Diversity 82: 42 (2016)

Index Fungorum: IF 552029

Known distribution: Thailand.

Habitat: Terrestrial.

Notes: Tubeufia longiseta was introduced by Dai et al. (2017) based on phylogeny and morphological evidence.


Tubeufia mackenziei Y.Z. Lu, Boonmee & K.D. Hyde, Mycol. Progr. 16(4): 411 (2017)

Index Fungorum: IF 818988

Known distribution: Thailand.

Habitat: Aquatic.

Notes: Tubeufia mackenziei was introduced by Lu et al. (2017b) based on phylogeny and morphological evidence.


Tubeufia minuta Munk, Bot. Notiser 119: 179 (1966)

Index Fungorum: IF 340544

Possible distribution: Denmark, Sweden.

Habitat: Terrestrial.

Notes: Tubeufia minuta was introduced by Munk (1966) based on morphology.


Tubeufia pachythrix (Rehm) Rossman, Mycotaxon 8(2): 534 (1979)

≡ Calonectria pachythrix Rehm, Annls mycol. 5(6): 531 (1907)

Index Fungorum: IF 325093

Known distribution: Brazil.

Habitat: Terrestrial.

Notes: This taxon was introduced as Calonectria pachythrix by Rehm (1907). Rossman (1979) synonymized it under Tubeufia pachythrix based on morphology.


Tubeufia palmarum (Torrend) Samuels, Rossman & E. Müll., Sydowia 31(1–6): 189 (1979) [1978]

≡ Ophionectria palmarum Torrend, Bull. Jard. bot. État Brux. 4: 8 (1914)

Index Fungorum: IF 325094

Possible distribution: Brazil, Colombia, Peru, Venezuela.

Habitat: Terrestrial.

Notes: Samuels et al. (1979) synonymized Ophionectria palmarum under Tubeufia palmarum based on morphological analyses.


Tubeufia parvula Dennis, Kew Bull. 30(2): 362 (1975)

Index Fungorum: IF 325096

Possible distribution: Britain, Sweden.

Habitat: Terrestrial.

Notes: Tubeufia parvula was introduced by Dennis (1975) based on morphology.


Tubeufia silentvalleyensis (V.G. Rao & Varghese) A. Pande [as ‘silentvalliensis’], Ascomycetes of Peninsular India (Jodhpur): 173 (2008)

≡ Thaxteriella silentvalliensis V.G. Rao & Varghese, Sydowia 32(1-6): 255 (1980) [1979]

Index Fungorum: IF 538022

Known distribution: India.

Habitat: Terrestrial.

Notes: This taxon was introduced as Thaxteriella silentvalliensis by Rao and Varghese (1979). Pande (2008) synonymized it under Tubeufia silentvalleyensis based on morphology.

Excluded Tubeufia species

Tubeufia helicomyces Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 118: 1477 (1909)

Index Fungorum: IF 244273

Notes: Tubeufia helicomyces was introduced by von Höhnel (1909). Tsui et al. (2006) provided DNA sequence data for their new isolates of T. helicomyces (MUCL 15702 and CBS 271.52). However, our phylogenetic tree (Fig. 2) showed that MUCL 15702 and CBS 271.52 cluster in different clade within the genus Neohelicomyces. Therefore, we exclude this species from the genus Tubeufia.

Other accepted genera in Tubeufiaceae

Acanthophiobolus Berl., Atti Congr. Bot. Intern. di Genova, 1892: 571 (1893)

Index Fungorum: IF 13

Type species: Acanthophiobolus helicosporus (Berk. & Broome) J. Walker, Trans. Br. mycol. Soc. 58(3): 445 (1972)

Possible distribution for type species: Australia, Britain, Belgium, Denmark, Germany, Morocco, New Zealand, Norway, Spain, USA.

Description: For a complete description of this genus see Boonmee et al. (2011).

Notes: Acanthophiobolus was introduced by Berlese (1893a) with Acanthophiobolus helicosporus as the type species (Berlese 1893a, as A. helminthosporus). Boonmee et al. (2011) reexamined the holotype of type species and accepted Acanthophiobolus as a member of Tubeufiaceae. Up to now, the genus Acanthophiobolus includes three species, viz. A. anogeissi, A. helicosporus and A. indicus (Walker 1980; Dharkar et al. 2006). No molecular data are available.


Acanthostigma De Not., Sfer. Ital.: 85 (1863)

Index Fungorum: IF 16

Type species: Acanthostigma perpusillum De Not., Sfer. Ital.: 207 (1863)

Possible distribution for type species: Austria, Britain, Canada, Costa Rica, Denmark, Grenada, India, Italy, Indonesia, Seychelles, Switzerland, France, USA, Venezuela.

Description: For a complete description of this genus see Boonmee et al. (2011, 2014).

Notes: Réblová and Barr (2000) reviewed the genus Acanthostigma and six species were accepted. Boonmee et al. (2011) introduced a new Acanthostigma species based on phylogenetic analyses and morphology. Index Fungorum (2018) lists 91 records of Acanthostigma. However, most of them have been synonymized to other genera. Boonmee et al. (2014) only accepted three species within the genus Acanthostigma, viz. the type species A. perpusillum, A. chiangmaiensis and A. minutum, but did not change the status of other Acanthostigma species. Based on previous studies, we accept seven Acanthostigma species in this study, viz. A. chiangmaiensis (Boonmee et al. 2014), A. ellisii (Réblová and Barr 2000), A. longisporum (Réblová and Barr 2000), A. minutum (Réblová and Barr 2000; Boonmee et al. 2014), A. patagonicum (Sanchez et al. 2012), A. perpusillum (Réblová and Barr 2000), A. revocatum (Réblová and Barr 2000).


Acanthostigmina Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 118: 1499 [39 repr.] (1909)

Index Fungorum: IF 19

Type species: Acanthostigmina minuta (Fuckel) Clem. & Shear, Gen. fung., Edn 2 (Minneapolis): 270 (1931)

Known distribution for type species: Germany.

Description: For a complete description of this genus see Boonmee et al. (2014).

Notes: The genus Acanthostigmina was introduced by von Höhnel (1909) with A. minuta as the type species. Boonmee et al. (2014) reported that A. minuta (ANM810, ANM818 and ANM238) are related to two strains of A. multiseptatum (ANM475 and ANM665) which represented the genus Acanthostigmina. Our phylogenetic analyses show that ANM810, ANM818 and ANM238 could be distinct species. However, none of them is ex-type strain and, therefore, we cannot reappraise them. Two Acanthostigmina species are so far accepted, viz. A. minuta and A. multiseptatum (Crane et al. 1998; Boonmee et al. 2014).


Aquaphila Goh, K.D. Hyde & W.H. Ho, Mycol. Res. 102(5): 588 (1998)

Index Fungorum: IF 27791

Type species: Aquaphila albicans Goh, K.D. Hyde & W.H. Ho, Mycol. Res. 102(5): 588 (1998)

Known distribution for type species: Australia, Thailand.

Description: For a complete description of this genus see Goh et al. (1998), Boonmee et al. (2014) and Hyde et al. (2016a).

Notes: The genus Aquaphila was introduced by Goh et al. (1998) based on the type species A. albicans. Castañeda-Ruíz et al. (2000) introduced the second species, A. edentata, based on morphology. Tsui et al. (2007) accepted Aquaphila as a member of Tubeufiaceae based on phylogenetic analyses. Boonmee et al. (2014) linked its sexual-asexual morphs based on phylogenetic evidence. Hyde et al. (2016a) reported a new record of A. albicans. Our phylogenetic analyses show that the genus Aquaphila shares a sister relationship to Chlamydotubeufia and Helicotubeufia (Fig. 2).


Bifrontia Norman, Bot. Notiser: 18 (1872)

Index Fungorum: IF 569

Type species: Bifrontia compactior Norman, Bot. Notiser: 19 (1872)

Known distribution for type species: Norway.

Description: For a complete description of this genus see Boonmee et al. (2014).

Notes: The genus Bifrontia was introduced by Norman (1872) to accommodate two species, B. compactior and B. laxa, but neither was designated as the type species. Boonmee et al. (2014) reexamined the holotype of B. compactior and designated it as the lectotype, and accepted Bifrontia as a genus of Tubeufiaceae based on its comparable morphological characteristics. No molecular data is available for Bifrontia species.


Boerlagiomyces Butzin, Willdenowia 8(1): 39 (1977)

Index Fungorum: IF 607

Type species: Boerlagiomyces velutinus (Penz. & Sacc.) Butzin, Willdenowia 8(1): 39 (1977)

Possible distribution for type species: Costa Rica, Indonesia.

Description: For a complete description of this genus see Boonmee et al. (2014).

Notes: The genus Boerlagiomyces was introduced by Butzin (1977) with B. velutinus as the type species. Crane et al. (1998) reviewed and accepted six species in Boerlagiomyces in the family Tubeufiaceae. The latest description of Boerlagiomyces was reported by Boonmee et al. (2014). Index Fungorum (2018) lists eight valid species in this genus. No molecular data is available for Boerlagiomyces species.


Helicangiospora Boonmee, Bhat & K.D. Hyde, Fungal Diversity 68(1): 259 (2014)

Index Fungorum: IF 550574

Type species: Helicangiospora lignicola Boonmee, Bhat & K.D. Hyde, Fungal Diversity 68(1): 262 (2014)

Known distribution for type species: Thailand.

Description: For a complete description of this genus see Boonmee et al. (2014).

Notes: The genus Helicangiospora was introduced by Boonmee et al. (2014) based on phylogeny and morphological evidence. The type species H. lignicola is the only accepted species in this genus.


Helicotubeufia Y.Z. Lu & J.K. Liu, Mycosphere 9(3): 500 (2018)

Index Fungorum: IF 554759

Type species: Helicotubeufia guangxiensis Y.Z. Lu & J.K. Liu, Mycosphere 9(3): 500 (2018)

Known distribution for type species: China (Guangxi).

Description: For a complete description of this genus see Liu et al. (2018).

Notes: The genus Helicotubeufia was introduced by Liu et al. (2018) based on phylogeny and morphological evidence. Three species were accepted in this genus, viz. The type species H. guangxiensis, H. hydei and H. jonesii.


Kamalomyces R.K. Verma, N. Sharma & Soni, Forest Fungi of Central India: 196 (2008)

Index Fungorum: IF 512509

Type species: Kamalomyces indicus R.K. Verma, N. Sharma & Soni, Forest Fungi of Central India: 196 (2008)

Known distribution for type species: India.

Description: For a complete description of this genus see Verma et al. (2008), Dubey and Neelima (2013), Boonmee et al. (2011, 2014) and Phookamsak et al. (2018).

Notes: The genus Kamalomyces was introduced by Verma et al. (2008) to accommodate K. indicus as its type species. Kamalomyces has unique characters and can be distinguished from other genera of Tubeufiaceae in the form of solitary, gregarious, subglobose to limoniform, short-stalked ascomata on a subiculum of black hyphae and lacking ostioles, bitunicate, broadly cylindrical to clavate asci and hyaline, vermiform, crowded, septate ascospores (Verma et al. 2008; Dubey and Neelima 2013; Boonmee et al. 2011, 2014; Niranjan and Sarma 2018; Phookamsak et al. 2018). Phookamsak et al. (2018) first reported the phylogenetic relationship of Kamalomyces and its asexual morph. Five species are accepted in this genus, viz. K. bambusicola, K. indicus, K. mahabaleshwarensis, K. polyseptatus and K. thailandicus (Verma et al. 2008; Dubey and Neelima 2013; Niranjan and Sarma 2018; Phookamsak et al. 2018).


Muripulchra Z.L. Luo, Hong Y. Su & K.D. Hyde, Cryptog. Mycol. 38(1): 36 (2017)

Index Fungorum: IF 818825

Type species: Muripulchra aquatica Z.L. Luo, Hong Y. Su & K.D. Hyde, Cryptog. Mycol. 38(1): 39 (2017)

Known distribution for type species: China (Yunnan)

Description: For a complete description of this genus see Luo et al. (2017).

Notes: The genus Muripulchra was introduced by Luo et al. (2017) based on phylogeny and morphological evidence. The type species M. aquatica is the only accepted species in this genus.


Neotubeufia Chaiwan, Boonmee, Y.Z. Lu & K.D. Hyde, Mycosphere 8(9): 1149 (2017)

Index Fungorum: IF 553871

Type species: Neotubeufia krabiensis Chaiwan, Boonmee, Y.Z. Lu & K.D. Hyde, Mycosphere 8(9): 1149 (2017)

Known distribution for type species: Thailand

Description: For a complete description of this genus see Chaiwan et al. (2017).

Notes: The genus Neotubeufia was introduced by Chaiwan et al. (2017) based on phylogeny and morphological evidence. The type species N. krabiensis is the only accepted species in this genus.


Podonectria Petch, Trans. Br. mycol. Soc. 7(3): 146 (1921)

Index Fungorum: IF 4280

Type species: Podonectria coccicola (Ellis & Everh.) Petch, Trans. Br. mycol. Soc. 7(3): 146 (1921)

Possible distribution for type species: Brazil, India, New Zealand, Puerto Rico, Sierra Leone, Switzerland, USA

Description: For a complete description of this genus see Pirozynski (1977) and Boonmee et al. (2011, 2014).

Notes: The genus Podonectria was introduced by Petch (1921) based on the type species P. coccicola. Its asexual morph was reported by Pirozynski (1977). Rossman (1978) reviewed this genus and accepted eight species. Boonmee et al. (2011) reexamined a specimen of P. coccicola identified by Rossman (1978). Boonmee et al. (2014) accepted Podonectria in the family Tubeufiaceae and pointed out that its sexual morphs were compatible with Tubeufiaceae, but asexual morphs are atypical. Index Fungorum (2018) lists nine valid Podonectria species. No molecular data is available for Podonectria species.


Tamhinispora Rajeshk. & Rah. Sharma, Mycosphere 4(2): 166 (2013)

Index Fungorum: IF 803105

Type species: Tamhinispora indica Rajeshk. & Rah. Sharma, Mycosphere 4(2): 167 (2013)

Known distribution for type species: India.

Description: For a complete description of this genus see Rajeshkumar et al. (2013, 2018).

Notes: The genus Tamhinispora was established by Rajeshkumar and Sharma (2013) with T. indica as its type species based on phylogeny and morphology. Rajeshkumar et al. (2018) introduced the second species, T. srinivasanii, based on phylogenetic analyses and morphology.


Thaxteriella Petr., Annls mycol. 22(1/2): 63 (1924)

Index Fungorum: IF 5408

Type species: Thaxteriella corticola Petr., Annls mycol. 22(1/2): 63 (1924)

Possible distribution for type species: Brazil, Puerto Rico.

Description: For a complete description of this genus see Boonmee et al. (2014).

Notes: The genus Thaxteriella was introduced by Petrak (1924). Linder (1929) and Sivanesan (1984) reported that Thaxteriella species produced a helicoma-like hyphomycetous asexual morph. Boonmee et al. (2011) reexamined the type material of T. corticola and verified Thaxteriella as a genus of Tubeufiaceae. Index Fungorum (2018) lists ten valid Thaxteriella species. No molecular data is available for Thaxteriella species.

Genera accepted in Bezerromycetaceae

Bezerromyces J.D.P. Bezerra, Souza-Motta & Crous, Mycol. Progr. 16: 301 (2017)

Index Fungorum: IF 817522

Type species: Bezerromyces brasiliensis J.D.P. Bezerra, Souza-Motta & Crous, Mycol. Progr. 16: 302 (2017)

Known distribution for type species: Brazil.

Description: For a complete description of this genus see Bezerra et al. (2017).

Notes: The genus Bezerromyces was established by Bezerra et al. (2017) to accommodate the type species Bezerromyces brasiliensis and B. pernambucoensis based on phylogeny and morphology.


Neorhamphoria Boonmee, Hüseyın & Selçuk, Mycosphere 7(9): 1450 (2016)

Index Fungorum: IF 552704

Type species: Neorhamphoria garethjonesii Boonmee, Hüseyın & Selçuk, Mycosphere 7(9): 1451 (2016)

Known distribution for type species: Turkey.

Description: For a complete description of this genus see Boonmee et al. (2016).

Notes: Neorhamphoria was introduced as a genus incertae sedis of Tubeufiales by Boonmee et al. (2016) based on phylogenetic evidence, and it is characterized by dark apothecial ascomata, broad cellular pseudoparaphyses, with bitunicate, broad-clavate asci, and hyaline, muriform ascospores. However, our multi-gene phylogenetic analyses indicate that Neorhamphoria grouped within Bezerromycetaceae (Tubeufiales) (Liu et al. 2018) and shares a sister relationship to Xiliomyces and Bezerromyces with high bootstrap support (Fig. 81). Hence, Neorhamphoria should be a genus of Bezerromycetaceae. Furthermore, its morphology resembles Xiliomyces in asci and ascospores, but is distinct from other members of Tubeufiales. Therefore, we transfer the genus Neorhamphoria to Bezerromycetaceae.

Fig. 81
figure 81

Phylogram generated from maximum likelihood analysis based on combined LSU, SSU and TEF1α sequence data (with Dendrographa decolorans as outgroup). Fifty-two strains are included in the combined sequence analyses which comprise 2,752 characters with gaps (854 characters for LSU, 1013 for SSU and 885 for TEF1α). Single gene analyses were also performed and tree topology and lade stability compared. The best scoring RAxML tree with a final likelihood value of − 15849.009182 is presented. RAxML bootstrap support values equal to or greater than 75% are given before the forward slash. Maximum parsimony bootstrap support values equal to or greater than 75% are given after the forward slash. Branches with bayesian posterior probabilities equal to or higher than 0.95 are in bold. Hyphen (‘-’) indicates a value lower than 75% for RAxML and Maximum parsimony

Full size image

Xiliomyces J.D.P. Bezerra, Souza-Motta & Crous, Mycol. Progr. 16: 304 (2017)

Index Fungorum: IF 817525

Type species: Xiliomyces brasiliensis J.D.P. Bezerra, Souza-Motta & Crous, Mycol. Progr. 16: 304 (2017)

Known distribution for type species: Brazil.

Description: For a complete description of this genus see Bezerra et al. (2017).

Notes: The genus Xiliomyces was established by Bezerra et al. (2017) with Xiliomyces brasiliensis as its type species based on phylogeny and morphology.

Genera accepted in Wiesneriomycetaceae

Parawiesneriomyces Crous & M.J. Wingf., Persoonia 36: 389 (2016)

Index Fungorum: IF 817060

Type species: Parawiesneriomyces syzygii Crous & M.J. Wingf., in Crous et al., Persoonia 36: 389 (2016)

Known distribution for type species: France.

Description: For a complete description of this genus see Crous et al. (2016).

Notes: The genus Parawiesneriomyces was established by Crous et al. (2016) with Parawiesneriomyces syzygii as its type species based on phylogeny and morphology.


Pseudogliophragma Phadke & V.G. Rao, Norw. J. Bot. 27(2): 127 (1980)

= Ramaraomyces N.K. Rao, Manohar. & Goos, Mycologia 81(5): 790 (1989)

Index Fungorum: IF 9579

Type species: Pseudogliophragma indica Phadke & V.G. Rao, Norw. J. Bot. 27(2): 127 (1980)

Known distribution for type species: India.

Description: For a complete description of this genus see Phadke and Rao (1980) and Pratibha et al. (2015).

Notes: The genus Pseudogliophragma was established by Phadke and Rao (1980) with Pseudogliophragma indica as its type species based on morphology. Pratibha et al. (2015) first reported its phylogenetic relationships and treated Ramaraomyces as a synonym.


Speiropsis Tubaki, J. Hattori bot. Lab. 20: 171 (1958)

Index Fungorum: IF 9965

Type species: Speiropsis pedatospora Tubaki, J. Hattori bot. Lab. 20: 171 (1958)

Possible distribution for type species: Brazil, India, Japan.

Description: For a complete description of this genus see Tubaki (1958) and Pratibha et al. (2016).

Notes: The genus Speiropsis was established by Tubaki (1958) with Speiropsis pedatospora as its type species based on morphology. Pratibha et al. (2016) treated Speiropsis as a member of Wiesneriomycetaceae based on phylogeny and morphology.


Wiesneriomyces Koord., Verh. K. Akad. Wet., tweede sect. 13(4): 246 (1907)

Index Fungorum: IF 10438

Type species: Wiesneriomyces laurinus (Tassi) P.M. Kirk, Trans. Br. mycol. Soc. 82(4): 748 (1984)

Possible distribution for type species: Australia, Brazil, Britain, China (Taiwan), Cuba, India, Indonesia, Ireland, Japan, Java, Malaysia, Mexico, New Zealand, Panama, Papua New Guinea, Thailand, USA, Vanuatu.

Description: For a complete description of this genus see Kirk (1984) and Suetrong et al. (2014).

Notes: The genus Wiesneriomyces was established by Koorders (1907) with Wiesneriomyces javanicus as the type species based on morphology. Kirk (1984) synonymized Wiesneriomyces javanicus under W. laurinus. Suetrong et al. (2014) first reported its phylogenetic relationships. Three species were accepted in this genus, viz. Wiesneriomyces conjunctosporus, W. laurinus and W. machilicola (Suetrong et al. 2014; Li et al. 2017).

Discussion

The modern classification of the order Tubeufiales was established by Boonmee et al. (2014) based on phylogenetic analyses and morphology. Subsequently, several new taxa were introduced mainly based on phylogenetic evidence (Hyde et al. 2016a, b, 2017; Brahamanage et al. 2017; Chaiwan et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Liu et al. 2018; Phookamsak et al. 2018). However, there were still many taxonomic problems in this group, especially in those with helicosporous asexual morphs. Our previous studies revealed that morphologically similar helicosporous taxa can be segregated based on DNA sequence data (Lu et al. 2017c, 2018; Luo et al. 2017; Liu et al. 2018). With further collections and additional phylogenetic analyses in this study, we have revised the taxonomy of those fungi and in particular help to highlight those which were misidentified and rectified which morphs are important in classifying species.

In this study, we reappraised known taxa of Tubeufiales and studied 118 newly obtained isolates based on phylogeny and morphology. We introduced 13 new genera, 52 new species, 43 new combinations and 16 new records, accepted three genera incertae sedis into the family Tubeufiaceae and the genus Neorhamphoria into the family Bezerromycetaceae.

Our phylogeny-morphology analyses confirmed that the order Tubeufiales with the family Tubeufiaceae, comprises 42 genera, viz. Acanthohelicospora, Acanthophiobolus, Acanthostigma, Acanthostigmina, Acanthotubeufia, Aquaphila, Artocarpomyces, Berkleasmium, Bifrontia, Boerlagiomyces, Chaetosphaerulina, Chlamydotubeufia, Dematiohelicoma, Dematiohelicomyces, Dematiohelicosporum, Dematiotubeufia, Dictyospora, Helicangiospora, Helicoarctatus, Helicodochium, Helicohyalinum, Helicoma, Helicomyces, Helicosporium, Helicotruncatum, Helicotubeufia, Kamalomyces, Muripulchra, Neoacanthostigma, Neochlamydotubeufia, Neohelicoma, Neohelicomyces, Neohelicosporium, Neotubeufia, Podonectria, Pleurohelicosporium, Pseudohelicomyces, Pseudohelicoon, Tamhinispora, Thaxteriella, Thaxteriellopsis and Tubeufia. The checklist of accepted Tubeufiales species (shown in Table 2) and re-organised Tubeufiales species (shown in Table 3) are provided here.

Table 2 Checklist of accepted Tubeufiales species
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Table 3 Checklist of re-organised Tubeufiales species
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Sexual morphs in Tubeufiaceae

We have reappraised and summarized the sexual morphs of Tubeufiaceae based on our new collections and previous studies (Brahamanage et al. 2017; Chaiwan et al. 2017; Lu et al. 2017a, b, c; Hyde et al. 2017; Liu et al. 2018; Phookamsak et al. 2018). The typical morphological characters of the sexual morphs of Tubeufiales are shown in Figs. 82 and 83. They are characterized by superficial, globose to subglobose, oval to obovate, to ellipsoid, mostly coriaceous, centrally ostiolate, white to yellow, pale brown to black ascomata with or without setae and seated on a subiculum; setae sparse to dense, straight to flexuous, covering the whole ascoma, unbranched, rounded at apical end or tapering to an acute tip at apex, septate, brown to dark brown; peridium comprising yellow to pale brown to black cells of textura angularis, and subhyaline to yellow to pale brown textura prismatica cells at innermost layers; hamathecium comprising numerous filiform, septate, branched, hyaline pseudoparaphyses; asci 8-spored, bitunicate, saccate, cylindric, with or without an ocular chamber, pedicellate or sessile, hyaline, smooth-walled; ascospores fasciculate in ascus, filiform to fusiform, straight to slightly curved, multi-septate, hyaline to pale brown, guttulate, smooth-walled.

Fig. 82
figure 82

Ascomata of Tubeufiaceae. a–y Superficial ascomata on decaying woody substrate. Scale bars: a–y = 200 µm

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Fig. 83
figure 83

Asci and ascospores of Tubeufiaceae. 1–11 Asci. 12–37 Ascospores. Scale bars: 1–11 = 50 µm, 12–37 = 20 µm

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Dictyosporous, helicosporous and phragmosporous asexual morphs in Tubeufiaceae

There are three kinds of hyphomycetous asexual morphs found in Tubeufiaceae, viz. dictyosporous, helicosporous and phragmosporous.

Dictyosporous hyphomycetes were reported in Berkleasmium, Chlamydotubeufia, Dictyospora, Kamalomyces and Tamhinispora (Boonmee et al. 2011; Rajeshkumar and Sharma 2013; Tanney and Miller 2017; Phookamsak et al. 2018). In this study, we found that the genus Tubeufia can also form dictyosporous hyphomycetous asexual morphs which is supported through phylogenetic evidence. Furthermore, we accepted the genus Artocarpomyces, possessing dictyosporous hyphomycetes, as a member of Tubeufiaceae based on its conidia and conidiogenous cell morphology, resembling Tubeufia dictyospora and T. chlamydospora.

Helicosporous hyphomycetes are the most common asexual morph in the order Tubeufiales. They are known to be present in many genera, such as Acanthohelicosporium, Chlamydotubeufia, Helicangiospora, Helicoma, Helicomyces, Helicosporium, Helicotubeufia, Neocanthostigma, Neohelicomyces, Neohelicosporium and Tubeufia (Boonmee et al. 2011, 2014; Hyde et al. 2016a; Brahamanage et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Liu et al. 2018). In this study, we introduced nine new helicosporous genera based on phylogenetic and morphological evidence, viz. Dematiohelicoma, Dematiohelicomyces, Dematiohelicosporum, Helicoarctatus, Helicohyalinum, Helicotruncatum, Neohelicoma, Pseudohelicomyces and Pseudohelicoon. Besides, we accept Berkleasmium and Helicodochium as the members of Tubeufiaceae based on phylogenetic analyses and morphology. These two genera also form helicosporous hyphomycetous asexual morphs.

Phragmosporous hyphomycetes in Tubeufiaceae were also found in Aquaphila and Helicoma. The genus Aquaphila including two species, both the type species Aquaphila albicans and A. edentata form phragmosporous asexual morphs (Goh et al. 1998; Castañeda-Ruíz et al. 2000; Tsui et al. 2007; Hyde et al. 2016a). Moreover, Matsushima (1983) reported the cultures of Helicoma taiwanensis producing phragmosporous conidia.

How to identify helicosporous hyphomycetes of Tubeufiaceae?

Helicosporous hyphomycetes are characterized by conidia that curve through at least 180° in one plane as they extend in length (Linder 1929; Goos 1980, 1985, 1986, 1989; Tsui et al. 2006; Luo et al. 2017). Helicoma, Helicomyces and Helicosporium are the three earliest described helicosporous hyphomycete genera. These genera were delineated by Linder (1929) and Goos (1980, 1985, 1986, 1989) based on different aspects of conidia and conidiophores. This scheme is still being followed to identify helicosporous species (Zhao et al. 2007; Boonmee et al. 2014; Hyde et al. 2016a; Brahamanage et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017). However, there is still vague terminologies and confusion to recognize helicosporous fungi, and identification remains controversial and divergent in opinion. Morgan (1892) proposed using the term “hygroscopic” to describe conidial nature of certain species in helicosporous fungi. Linder (1929) and Moore (1955) applied this feature to separate Helicoma from Helicomyces and Helicosporium. Pirozynski (1972) suggested that the taxonomy of those three genera might be improved by putting more importance on the characters of conidiogenous cells, conidial attachment position and secondary conidia, than on colour, size and configuration of conidiophores and conidial filaments. Goos (1985, 1986, 1989) reappraised and reviewed these three genera and proposed some informative characters to distinguish them, viz. the conidia of Helicoma are non-hygroscopic and the conidial filaments are relatively thick in proportion to their length; the conidia of Helicomyces and Helicosporium are hygroscopic and conidial filaments are thin in proportion to their length; the conidiophores are well-developed in Helicosporium, but much reduced or lacking in Helicomyces.

However, as DNA sequencing techniques have been applied to fungal taxonomy, several studies have shown that some helicosporous hyphomycetes which bear morphological resemblance do not belong to Helicomyces, Helicosporium or Helicoma (Boonmee et al. 2014; Sri-Indrasutdhi et al. 2015; Hyde et al. 2016a; Brahamanage et al. 2017; Lu et al. 2017a, b, c, 2018; Luo et al. 2017; Liu et al. 2018). These studies have indicated that there might have been considerable misidentification within these three genera. Our present study also provides strong evidence to support many species in these genera have been wrongly identified.

How to determine which morphological characters are phylogenetically informative for delimiting helicosporous fungi? Are hygroscopic conidia and similar morphology really most important? Do conidiophores and conidiogenous cell morphology play a secondary role? There are three species, Neohelicomyces hyalosporus, Neohelicosporium parvisporum and Tubeufia parvispora which share the same conidial morphology, including their size and colour and although they possess a distinct conidiophore morphology, we are likely to identify them as Helicosporium species based on previous studies and on morphological characters only. However, DNA sequence data clearly demonstrates that they belong to different genera and conidial morphology alone is not enough to separate them, even at the genus level. Furthermore, we found that conidiophore and conidial size as well as colour are also important to recognize species. For example, Tubeufia sympodilaxispora resembles T. sympodihylospora in conidiophore and conidia characters, but can be distinguished by their conidiophore size; Neohelicosporium hyalosporum resembles N. parvisporum in conidiophore and conidia characters, but can be distinguished by their conidial size; Helicotubeufia guangxiensis (Liu et al. 2018) is similar to Berkleasmium aquaticum (Lu et al. 2017c, as Neoacanthostigma aquaticum) in conidiophore and conidial morphology, but can be easily distinguished by their colour.

With respect to Helicomyces, Helicosporium, Helicoma and our new collections and known helicosporous taxa, we consider that the morphology of the conidiophore is most important to identify species at the genus level, whereas conidiophores and conidiogenous cells, as well as conidia (including their size and colour) are important to distinguish taxa at the species level. These morphological characteristics must be studied together to properly identify them. Following this approach, we have summarized the morphology for helicosporous members accepted in Tubeufiaceae and a key to those genera is provided here, except for Chlamydotubeufia, Helicangiospora, Neocanthostigma and Thaxteriellopsis, as those helicosporous asexual morphs were found from cultures and their morphology might be different to those examined on natural substrates. Furthermore, for the common and confusing genera, viz. Berkleasmium, Helicoma, Helicomyces, Helicosporium, Neohelicosporium and Tubeufia, we provide a genus level illustration to show their typical morphological characteristics (Figs. 84, 85, 86, 87, 88, 89). The characters shown in Figs. 84, 85, 86, 87, 88, and 89 can be used to delineate species and are supported by phylogenetic data.

Fig. 84
figure 84

Helicosporous asexual morph of Berkleasmium. a–f Colony on decaying wood. g–n Conidiophores. o–v Conidia. Scale bars: a–f = 200 µm, g–n = 20 µm, o–v = 50 µm

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Fig. 85
figure 85

Helicosporous asexual morph of Helicoma. a1–a6 Colony on decaying wood. b–g Conidiophores. h–n Conidiogenous cells. o–x Conidia. Scale bars: a1–a6 = 100 µm, b–g, w, x = 50 µm, h–n = 10 µm, o–v = 20 µm

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Fig. 86
figure 86

Helicosporous asexual morph of Helicomyces. a–c Colony on decaying wood. d–h Conidiophores. i–n Conidia. Scale bars: d–h = 20 µm, i–n = 50 µm

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Fig. 87
figure 87

Helicosporous asexual morph of Helicosporium. a–f Colony on decaying wood. g–k Conidiophores. l–q Conidiogenous cells. r–v Conidia. Scale bars: a–f = 100 µm, g–k = 50 µm, l–v = 10 µm

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Fig. 88
figure 88

Helicosporous asexual morph of Neohelicosporium. a1–a6 Colony on decaying wood. b–f Conidiophores. g–m Conidiogenous cells. n–w Conidia. Scale bars: a1–a6 = 200 µm, b–f = 20 µm, g–w = 10 µm

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Fig. 89
figure 89

Helicosporous asexual morph of Tubeufia. a1–a8 Colony on decaying wood. b–e, g–j Conidiophores. f Conidiophore with attached conidium. k–p Conidiogenous cells. q–x Conidia. Scale bars: a1, a4 = 100 µm, a2, a3, a5–a8 = 200 µm, b = 50 µm, c–l, q–x = 20 µm, m–p = 10 µm

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Key to helicosporous genera of Tubeufiaceae (found on natural decaying wood)

1. Fresh colonies on decaying woody substrate are dematiaceous ……… 2

1. Fresh colonies on decaying woody substrate are hyaline ……… 11

2. Conidia tightly coiled in a clockwise direction to formed a subglobose or broadly elliptical body …………… Pseudohelicoon

2. Conidia helicoid but not forming a subglobose or broadly elliptical body …………… 3

3. Colonies yellow to greenish yellow ……… 4

3. Colonies pink, pale brown to dark brown …………… 5

4. Conidiophores setiferous, brown to dark brown, > 350 μm long, conidiogenous cells bladder-like projections ……… Acanthohelicospora

4. Conidiophores setiferous, brown to dark brown, conidia pleurogenous, < 25 μm diam., conidial filament < 4 μm wide ……… Helicosporium

5. Conidiophores arising from a pseudoparenchymatous stromata ……… Helicodochium

5. Conidiophores arising from creep hyphae, lacking a pseudoparenchymatous stromata ……… 6

6. Conidiophores < 50 μm long ……… 7

6. Conidiophores > 50 μm long ……… 8

7. Conidiophores 0–3-septate, brown, conidia < 90 μm diam., rounded at apex, truncate at basal cell, and elongated, indistinctly multi-septate, olivaceous to brown ……… Dematiohelicosporum

7. Conidiophores 0–3-septate, brown, conidia > 90 μm diam., rounded at apex and base, distinct multi-septate, pale brown to brown ……… Berkleasmium

8. Conidia pleurogenous, conidial filament < 5 μm wide ……… Pleurohelicosporium

8. Conidia acropleurogenous or pleurogenous, conidial filament > 5 μm wide ……… 9

9. Conidia acropleurogenous, the basal cell truncate with thickened lateral walls, dilute fuliginous ……… Helicotruncatum

9. Conidia acropleurogenous or pleurogenous, hyaline to brown ……… 10

10. Conidia rounded at apex, tapering gradually towards truncate basal cell, multi-septate, dark brown septa ……… Dematiohelicoma

10. Conidia tapering towards apex, rounded at apex, hyaline to brown ……… Helicoma

11. Conidiophores 0–3-septate ……… 12

11. Conidiophores multi-septate ……… 14

12. Conidiophores pale brown, conidiogenous cells terminal, cylindrical, truncate at apex after conidial secession, hyaline to pale brown ……… Dematiohelicomyces

12. Conidiophores hyaline, conidiogenous cells terminal, cylindrical, hyaline ……… 13

13. Conidiogenous cells terminal, tapering towards apex, inverted funnel at apex, conidia hygroscopic, tightly coiled 2½–3½ times, not becoming loose in water, easy to deform and fracture ……… Helicohyalinum

13. Conidiogenous cells terminal, cylindrical, truncate at apex after conidial secession, conidia dry, attached eccentrically and seceding schizolytically, end cells broadly spathulate coiled 1½–3¾ times, and becoming loosely coiled in water ……… Helicomyces

14. Conidiophores setiferous, unbranched, brown to dark brown, conidiogenous cells discrete, arising laterally from lower portion of the conidiophores as tiny tooth-like protrusions, each bearing 1–2 tiny sporogenous conidiogenous loci ……… Helicoarctatus

14. Conidiophores branched and unbranched, hyaline to brown ……… 15

15. Conidiogenous cells terminal and intercalary, cylindrical, with a truncate apex ……… 16

15. Conidiogenous cells terminal and intercalary, cylindrical, denticulate ……… 17

16. Mycelium from natural woody substrate, hyaline, conidiophores hyaline, conidia hyaline, conidial filament > 7 μm wide ……… Helicotubeufia

16. Mycelium from natural woody substrate, brown, conidiophores pale brown to brown, conidia hyaline to pale brown ……… Tubeufia

17. Conidiophores hyaline to brown, mostly unbranched, > 110 μm long ……… Neohelicomyces

17. Conidiophores irregular, 20–450 μm long, pale brown to dark brown ……… 18

18. Conidiophores branched, brown to dark brown, with many short pale brown branches, conidia mostly loosely coiled ……… Pseudohelicomyces

18. Conidiophores occasionally branched, brown to dark brown, conidia similar to Helicosporium, tightly coiled, and becoming loosely coiled in water ……… Neohelicosporium

Tubeufiaceous taxa from freshwater habitats

Freshwater fungi play an important role in nutrient cycling and ecosystem functioning (Wong et al. 1998; Hyde et al. 2016b; Vijaykrishna et al. 2006; Shearer et al. 2009). Many freshwater fungi are distributed in the classes Dothideomycetes and Sordariomycetes of the Ascomycota (Jeewon et al. 2003; Tsui and Hyde 2004; Vijaykrishna et al. 2005, 2006; Zhang et al. 2008a, b; Shearer et al. 2009; Hyde et al. 2013; Maharachchikumbura et al. 2015; Su et al. 2018). Based on previous studies, most of the tubeufiaceous taxa are saprobic on terrestrial woody substrates and only a few are from aquatic habitats (Barr 1979; Barr 1980; Rossman 1987; Goh et al. 1998; Kirk et al. 2001; Ho et al. 2002; Cai et al. 2003; Zhao et al. 2007; Boonmee et al. 2011, 2014; Doilom et al. 2017). However, during our study on lignicolous freshwater fungi along a north-south latitudinal gradient in Asia (Hyde et al. 2016b), more and more tubeufiaceous taxa are being recovered from submerged wood in freshwater streams in China and Thailand (Hyde et al. 2016a; Brahamanage et al. 2017; Chaiwan et al. 2017; Lu et al. 2017b, c, 2018; Luo et al. 2017; Liu et al. 2018). In this study, most of our new tubeufiaceous taxa are collected from freshwater habitats, and one interesting finding is that asexual morphs, especially the helicosporous hyphomycetes, are more common than the sexual morphs in aquatic habitats. There are at least 89 asexual tubeufiacous species known from freshwater (Goh and Hyde 1996; Goh et al. 1998; Rajeshkumar and Sharma 2013; Hyde et al. 2016a, b, 2017; Brahamanage et al. 2017; Chaiwan et al. 2017; Lu et al. 2017b, c, 2018; Luo et al. 2017; Goh and Kuo 2018; Kuo and Goh 2018a, b; Liu et al. 2018; Rajeshkumar et al. 2018; this study), but only 18 sexual morph species are found from freshwater habitats, viz. Berkleasmium aquaticum, B. thailandicum, Chlamydotubeufia cylindrica, C. krabiensis, Dictyospora thailandica, Helicosporium flavum, Helicotubeufia guangxiensis, H. hydei, H. jonesii, Neochlamydotubeufia fusiformis, Neohelicosporium ellipsoideum, Neotubeufia krabiensis, Thaxteriellopsis lignicola, Tubeufia claspisphaeria, T. filiformis, T. guangxiensis, T. latispora and T. tectonae (Brahamanage et al. 2017; Chaiwan et al. 2017; Hyde et al. 2017; Lu et al. 2017b, c; Liu et al. 2018; This study). Up to now, tubeufiaceous taxa from freshwater habitats are distributed in 23 genera, viz. Aquaphila, Berkleasmium, Chlamydotubeufia, Dematiohelicomyces, Dictyospora, Helicoarctatus, Helicodochium, Helicohyalinum, Helicoma, Helicomyces, Helicosporium, Helicotubeufia, Kamalomyces, Muripulchra, Neochlamydotubeufia, Neohelicomyces, Neohelicosporium, Neotubeufia, Pseudohelicomyces, Pseudohelicoon, Tamhinispora, Thaxteriellopsis and Tubeufia.