Taxonomic revision of Rinorea ilicifolia (Violaceae) from Africa and Madagascar

Summary

The uncertain taxonomic circumscription between Rinorea ilicifolia (Welw. ex Oliv.) Kuntze and R. spinosa (Boivin ex Tul.) Baill. has led to considerable confusion when attempting to identify the two species. The plants from mainland Africa have typically been determined as R. ilicifolia while the plants in Madagascar and the Comoro Islands have been variously assigned to R. spinosa, R. ilicifolia, or R. ilicifolia subsp. spinosa (Boivin ex Tul.) Grey-Wilson. A third taxon from east Africa, R. ilicifolia var. amplexicaulis Grey-Wilson, has auriculate leaf bases and a mostly discrete distribution from R. ilicifolia, suggesting a greater degree of divergence than is indicated by its taxonomic rank of variety. To better understand the circumscription among these three taxa, we performed multivariate and discriminant analyses of six quantitative variables measured from herbarium specimens. Based on results from these analyses, we deemed there was insufficient morphological divergence to maintain R. ilicifolia and R. spinosa as separate species. Instead, we recognise a single species, R. ilicifolia, composed of three subspecies: R. ilicifolia subsp. ilicifolia in mainland Africa, R. ilicifolia subsp. spinosa in Madagascar and the Comoro Islands, and R. ilicifolia subsp. amplexicaulis (Grey-Wilson) Wahlert, comb. et stat. nov. from Tanzania and Burundi. Here we provide a taxonomic revision of R. ilicifolia, a distribution map and preliminary risk of extinction assessment using IUCN Red List categories and criteria for the three subspecies. We also propose a change of status for Rinorea [unranked] Ilicifoliae Engl. to the rank of section, an action supported by phylogenetic and morphological evidence. The new section includes R. ilicifolia and 13 other taxa from mainland Africa. Lectotypes are designated for the section and for Alsodeia spinosa Boivin ex Tul., and a second-step lectotype is selected for Alsodeia ilicifolia Welw. ex Oliv.

Introduction

Rinorea Aubl. is the second most species-rich genus in the Violaceae and is composed of c. 250 species of shrubs and small trees occurring in humid and seasonally dry forests across the tropics (Ballard et al. 2014). In mainland Africa, there are approximately 150 species, with Cameroon and Gabon being particularly rich in species (Robson 1960; Tennant 1963; Grey-Wilson 1986; Velzen et al. 2015). Madagascar is another centre of endemism for the genus with 27 accepted species, 80% of which are endemic (Madagascar Catalogue 2018). The Comoro Islands harbour six species that are shared with either Africa or Madagascar or both (Wahlert 2010).

Alsodeia spinosa Boivin ex Tul. from Madagascar and A. ilicifolia Welw. ex Oliv. from Angola were described at nearly the same time (but see below), with Baillon (1886) and Kuntze (1891) making the respective new combinations under Rinorea: R. spinosa (Boivin ex Tul.) Baill. and R. ilicifolia (Welw. ex Oliv.) Kuntze. Since then, the name R. ilicifolia has been applied to the African plants, whereas specimens from Madagascar and the Comoro Islands are variously identified or annotated as R. spinosa (e.g. Bâthie 1954; Robson 1960; R. Capuron in sched.), R. ilicifolia subsp. ilicifolia (e.g. Tennant 1963; J.-N. Labat in sched.; Achoundong & Cheek 2005; R. Capuron in sched., C. C. H. Jongkind in sched.), or R. ilicifolia subsp. spinosa (Boivin ex Tul.) Grey-Wilson (e.g., Grey-Wilson 1981; S. Wohlhauser in sched., L. Gautier & N. Messmer in sched.). The main goal of this study was to re-examine the taxonomic boundaries between R. ilicifolia and R. spinosa using multivariate and discriminant analyses. We also examined several specimens of R. ilicifolia var. amplexicaulis Grey-Wilson from Burundi and Tanzania — an easily recognised taxon with auriculate leaf bases and a mostly non-overlapping geographic distribution from R. ilicifolia subsp. ilicifolia. These three taxa, along with R. letouzeyi Achound., represent the only species with typically spinose leaf margins in Rinorea [unranked] Ilicifoliae Engl.; the remaining taxa have subentire to serrate margins. Species in Ilicifoliae are delimited by various combinations of characters, including: presence or absence of glands on the lower leaf surface, leaf shape, pubescence patterns on young stems and inflorescence axes, morphology of the inflorescence and androecium, and fruit shape.

Results from previous molecular phylogenetic analyses did not resolve species-level relationships among Rinorea ilicifolia and other closely related taxa in the informally named Ilicifoliae clade (Wahlert & Ballard 2012; Velzen et al. 2015). In both studies, species in the clade were recovered in one of two monophyletic groups that corresponded geographically to a mostly west African subclade and a Madagascar-Comoro Islands-southeastern Africa subclade (Fig. 1). Rinorea spinosa and R. ilicifolia var. amplexicaulis were each resolved in weakly to moderately supported monophyletic groups, while R. ilicifolia was polyphyletic, with exemplars of the species recovered in both subclades. Even though results from those studies do not help inform taxonomic circumscription, the pattern of phylogenetic relationships does suggest a peripheral isolates mode of speciation. In the case of R. spinosa, a southern or eastern African ancestor of R. ilicifolia likely dispersed to Madagascar (or the Comoro Islands) at some time in the last 4.5 million years, giving rise to R. spinosa and rendering R. ilicifolia as non-monophyletic (Velzen et al., unpubl. data). Alternatively, the plastid and nuclear markers used in those studies may not have been variable enough to resolve species-level relationships.

Fig. 1

Consensus cladogram of phylogenetic relationships in Rinorea sect. Ilicifoliae (Engl.) Wahlert based on Wahlert & Ballard (2012) and van Velzen et al. (2015). Black circles indicate combined branch support of ≥ 95% MP bootstrap and ≥ 0.99 BI posterior probability.

There is no genus-wide infrageneric classification for Rinorea, but Wahlert (2010) has classified the African and Malagasy species into 11 infrageneric groups that correspond in part to groupings proposed by Engler (1904). Among these is Rinorea [unranked] Ilicifoliae, which was represented by the Ilicifoliae clade in phylogenetic studies and shown to be a well-supported clade based on analyses of plastid and nuclear DNA sequences (Wahlert & Ballard 2012; Velzen et al. 2015). In the study of Wahlert & Ballard (2012), branch support for the Ilicifoliae clade was 92% maximum parsimony (MP) bootstrap (BS), 90% maximum likelihood (ML) BS, and 0.99 Bayesian inference (BI) posterior probability (PP), with similarly high support in Velzen et al. (2015): 91% ML BS and 1.0 BI PP. Fig. 1 shows a MP consensus cladogram of members of the Ilicifoliae clade based on a combined analysis of taxa and data used in both studies (phylogenetic analysis follows Wahlert & Ballard 2012).

Members of the Ilicifoliae clade are readily circumscribed from other African and Malagasy infrageneric groups by a combination of morphological characters, including: alternately arranged leaves, narrowly cylindrical thyrsoid inflorescences, spherical-ovoid flower buds, a zygomorphic calyx with sepals prominently nerved longitudinally, a weakly zygomorphic corolla, staminal tube with the margin of the tube deeply sinuate between insertion of anthers, six ovules per ovary, and elliptic-ovoid to obovoid capsules containing six yellow-brown seeds. Truly actinomorphic floral symmetry has not been observed for any species in the Violaceae, and magnified observation of flower dissections are needed to reveal the zygomorphy of the calyx and corolla in most species of Rinorea, including R. ilicifolia (Wahlert et al. 2014). There is now ample evidence from molecular phylogenetic studies and morphological characters to recognise Engler's Rinorea [unranked] Ilicifoliae at the rank of section.

Materials and Methods

A total of 132 herbarium specimens from P and MO (herbarium abbreviations from Thiers, continuously updated) representing Rinorea ilicifolia, R. spinosa, and R. ilicifolia var. amplexicaulis were measured for morphometric analyses (Appendix). Six quantitative traits were scored from each specimen: petiole length, lamina length and width, number of secondary vein pairs, inflorescence length, and peduncle length. Examination of flowers and fruits were made from an additional c. 100 herbarium specimens from BM, G, K, PRE, TAN, TEF, and WAG. Study of c. 50 specimens found that floral morphology (shapes and sizes of the sepals, petals, androecium, and gynoecium) was not variable. Likewise, no differences were detected in the morphology of fruit and seed from c. 50 specimens of R. ilicifolia and R. spinosa (fruiting specimens of var. amplexicaulis were not available); flower and fruit characters were therefore excluded from analyses.

For multivariate and linear discriminant analyses, we measured 62 herbarium specimens of Rinorea ilicifolia, 64 of R. spinosa, and six of var. amplexicaulis (in the analyses, the three taxa are referred to as ilicifolia, spinosa, and amplexicaulis, respectively). Differences among the six measured quantitative morphological traits were assessed using parametric analysis of variance (ANOVA) and pairwise comparisons of means using Tukey-Kramer multiple comparisons tests when ANOVA yielded a significant F statistic. All residuals were examined for the assumption of normality using quantile-quantile plots and histograms. Levene’s test implemented the “car” package (Wuertz 2010) and was used to test for homogeneity of variance.

The ability of combined morphological measurements to distinguish Rinorea ilicifolia, R. spinosa, and R. ilicifolia var. amplexicaulis was examined using a linear discriminant analysis (LDA). LDA is a multivariate classification method that generates classification rules by maximising between-species variability in the data (James & McCulloch 1990; Henderson 2006) and was implemented using the MASS package (Venables & Ripley 2002). Taxonomic identification and a priori group assignment for LDA was based on geography for R. ilicifolia (Africa) and R. spinosa (Madagascar and Comoro Islands), and on leaf morphology for var. amplexicaulis (leaf base auriculate vs leaf base cuneate to rounded in R. ilicifolia and R. spinosa). LDA loadings were examined to understand which traits may be useful for distinguishing species. All analyses were conducted using the R statistical programming environment (R Development Core Team 2013).

Assessments of the preliminary risk of extinction were based on the IUCN Red List categories and criteria (IUCN 2012). The extent of occurrence (EOO) and area of occupancy (AOO) were based on 2 km² cells and were calculated using the Geospatial Conservation Assessment Tool (GeoCAT, Bachman et al. 2011). All specimens cited have been seen by the first author; abbreviations used in the list of specimens examined include: SF (Service Forestier [collector series]), RN (Réserves Naturelles: collector series or protected area), RS (Réserve Spéciale), PN (Parc National), NP (National Park), and RNI (Réserve Naturelle Intégrale). Our recognition of taxa at the rank of subspecies is based on the concept of Rietz (1930), where "a subspecies is a population of several biotypes forming a more or less distinct regional facies [appearance] of a species (p. 354)."

Results

Results of the multivariate analyses are summarised in Fig. 2. and Table 1. Leaf length (P = 0.413) and the length of the inflorescence (P = 0.158) did not vary among the three taxa. Rinorea ilicifolia had slightly wider leaves than R. spinosa, while R. ilicifolia var. amplexicaulis did not differ from either one (P < 0.001). Both R. spinosa and var. amplexicaulis had a similar number of secondary vein pairs (P < 0.001), while R. ilicifolia had fewer, and R. spinosa had longer peduncles than the other two taxa (P < 0.001). The only character that varied among all three taxa was petiole length (P < 0.001).

Fig. 2

Box plots showing the results of multivariate analyses of the six characters measured in the analyses.

Table 1. Mean values (range) for the six morphological characters measured in this study. Coefficients showing the results of multivariate analyses using morphological variables. LD1 and LD2 give the respective loadings for each variable in each discriminant function.

A scatterplot of the best two discriminant functions showed only moderate separation among the three taxa (Fig. 3). The first discriminant function achieved the most separation (92.06%), separating spinosa from ilicifolia and ilicifolia from amplexicaulis; the second discriminant function achieves fair separation of spinosa from amplexicaulis, accounting for 9.94% of the separation observed. The first discriminant function was mainly influenced by number of secondary vein pairs and leaf lamina width (Table 1), while the second discriminant function was mostly influenced by leaf lamina width followed by peduncle length (Table 2). The LDA misclassification rate was 7.5% (Table 2) indicating the allocation rule functioned reasonably well.

Fig. 3

Taxon assignment of 132 Rinorea individuals using linear discriminant analysis (LDA). The analysis is based on six morphological characters. LDA axis 1 accounts for 92.06% group separation; axis 2 accounts for the remaining 9.94% group separation.

Table 2. Classification of discriminant analysis of six characters with three predefined groups and the number of correctly classified cases based on LDA classification rule.

Discussion

Over the course of this study, examination of herbarium specimens and morphometric analyses have not revealed any single morphological character nor any combination of characters that reliably separate Rinorea ilicifolia from R. spinosa. Neither have we discovered any characters of flowers, fruits, or seeds that differentiate the three infraspecific taxa examined in this study. The lack of consistent and observable morphological distinctiveness between R. ilicifolia and R. spinosa becomes evident when they are examined side by side. Indeed, the pattern of variation between R. ilicifolia and R. spinosa aligns well with observations of a subspecies by Rietz (1930), where "...it is not always possible to tell from an isolated specimen in a collection to which subspecies it belongs, if the locality of the specimen or the range of the subspecies is unknown..." and that "...subspecies are best described by a statistical survey of the forms constituting it." With only slight trends in a few vegetative differences — which are nevertheless correlated with geographic distribution — and lacking any further evidence of reciprocal monophyly or ecological differentiation, we recognise a widely distributed R. ilicifolia composed of three subspecies: subsp. ilicifolia in Sub-Saharan Africa, subsp. spinosa in Madagascar and the Comoro Islands, and subsp. amplexicaulis in Tanzania and Burundi.

Taxonomic Treatment

Rinorea sect. Ilicifoliae (Engl.) Wahlert, comb. & stat. nov.

http://www.ipni.org/urn:lsid:ipni.org:names:77205198-1

Rinorea [unranked] Ilicifoliae Engl., Bot. Jahrb. Syst. 33: 133 (Engler 1904). Type: Rinorea ilicifolia (Welw. ex Oliv.) Kuntze (lectotype, designated here).

distribution. Sub-Saharan Africa, northern and western Madagascar, Mayotte and Comoros.

notes. Rinorea sect. Ilicifoliae includes 16 taxa: Rinorea abbreviata Achound. & Bos, R. afzelii Engl. var. afzelii, R. afzelii var. pubescens Taton, R. breteleri Achound., R. comperei Taton, R. crassifolia (Baker f.) De Wild., R. dewitii Achound., R. ilicifolia subsp. ilicifolia, R. ilicifolia subsp. spinosa, R. ilicifolia subsp. amplexicaulis (Grey-Wilson) Wahlert [name based on R. ilicifolia var. amplexicaulis; see below], R. keayi Brenan, R. letouzeyi Achound., R. mezilii Achound., R. prasina (Stapf) Chipp, R. simoneae Achound. and R. wagemansii Taton. Further systematic study within Rinorea sect. Ilicifoliae is needed to better understand relationships and species diversity among the included taxa.

1. Rinorea ilicifolia (Welw. ex Oliv.) Kuntze (1891: 42).

Shrub to 6 m tall, usually much less, evergreen; young branches glabrous to sparsely puberulent. Leaves alternate, subsessile to petiolate; petioles 2 – 40 mm long, glabrous to minutely puberulent or rarely pubescent, canaliculate on adaxial surface; stipules quickly caducous, lanceolate-deltoid, c. 8 – 10 × 1.5 – 2.3 mm, apex acute; lamina elliptic to elliptic-oblong or obovate, 7 – 26 × 2.4 – 9 (– 14.6) cm; glabrous on both surfaces or rarely pubescent on midvein abaxial surface; secondary vein pairs 4 – 14, divergent to ascending; base auriculate or cuneate to rounded; margin spinose, rarely serrate; apex acute to acuminate; domatia absent. Inflorescence a terminal, or rarely axillary, narrowly cylindrical panicle-like cyme, 2 – 16 cm long, lateral cymules bearing 2 – 9 flowers, axes glabrous to sparsely puberulent, rarely pubescent; peduncle 0.1 – 3.2 cm long; bracts and bracteoles triangular to ovate-deltoid, 0.8 – 3 × 0.8 – 2.1 mm, often keeled, outer surface glabrous to puberulent, rarely pubescent, margin ciliate, apex acute, often mucronate; pedicels 1 – 2 mm long, articulated at base, glabrous to puberulent, rarely pubescent. Flowers fragrant, buds ovoid. Calyx zygomorphic, sepals ovate to ovate-elliptic or orbicular, concave, 1.4 – 3.5 × 0.9 – 3.5 mm, carnose, nerved longitudinally, outer surface glabrous to pubescent, margin scarious, entire to ciliate, apex rounded. Corolla subzygomorphic, petals oblong-lanceolate to oblanceolate, concave, 2.8 – 4.4 × 0.7 – 2.3 mm, pale yellow, yellow-green, or cream, glabrous, inner surface sometimes puberulent near the middle; margin entire to ciliolate, apex rounded, usually recurved. Stamens 2.1 – 3 mm long; filaments connate into a staminal tube, staminal tube 0.2 – 0.4 mm tall, sinuate between insertion of anthers, inner and outer surfaces glabrous; anthers sessile on summit of staminal tube or filamented, filament 0.2 – 0.5 mm long, anther connectives 1.2 – 1.4 × 0.4 – 0.6 mm, glabrous; anther ventral connective scales 1 or 2, ovate, 0.3 – 0.6 × 0.1 – 0.4 mm, scarious, drying brown; anther dorsal connective scales large and conspicuous, ovate-lanceolate, 1.3 – 2 × 0.7 – 1.2 mm, scarious, drying orange-brown, glabrous, margin entire, apex rounded or rarely acute. Pistil 2.4 – 3.6 mm long; ovary ovoid, 0.5 – 1 × 0.5 – 1.1 mm, glabrous; ovules 6; style 1.6 – 2.4 mm long, erect, filiform, glabrous. Fruit a hard, 3-lobed capsule, dehiscent along 3 sutures, elliptic-ovoid to elliptic-obovoid, 1.2 – 1.9 cm long, 1 – 1.4 cm diam., valve 0.3 – 0.7 cm wide, surface glabrous, verrucose, brown at maturity; calyx persistent at base of mature fruit. Seeds 4.5 – 6.5 × 3.6 – 7 mm, irregular-tetrahedral, tan-coloured or yellow with light brown mottling, glabrous.

Key to the subspecies of Rinorea ilicifolia

• 1. Leaves subsessile; petioles ≤ 2(7) mm long; leaf base auriculate……....….1c. R. ilicifolia subsp. amplexicaulis

• Leaves petiolate; petioles 2 – 40 mm long; leaf base cuneate to rounded2

• 2. Petioles 2 – 27 mm long; leaf 2.4 – 8.3 cm wide; secondary vein pairs 7 – 14; peduncle 0.1 – 3.2 cm long; Madagascar and Comoro Islands1b. R. ilicifolia subsp. spinosa

• Petioles 5 – 40 mm long; leaf 2.5 – 14.6 cm wide; secondary vein pairs 4 – 10; peduncle 0.1 – 1.5 cm long; –Sub-Saharan Africa……....….1a. R. ilicifolia subsp. ilicifolia

1a. Rinorea ilicifolia (Welw. ex Oliv.) Kuntze subsp. ilicifolia. Alsodeia ilicifolia Welw. ex Oliv. (Oliver 1868: 108). Type: Angola, Pungo Andongo, Barrancos de Catete, Feb. 1857, Welwitsch 889 (lectotype LISU, designated by Tennant (1963: 409); second-step lectotype LISU [LISU206098!], designated here; isolectotypes BM [BM000617803!], M [M0109597!], LISU [LISU206100!], PRE0291990-0!).

Rinorea khutuensis Engl. (Engler 1900: 436). Rinorea ilicifolia var. khutuensis (Engl.) Tennant (1963: 411). Type: Tanzania, Khuta-steppe, Morogoro Distr., 300 m, 1898, Goetze 117 (holotype B, destroyed; isotypes BM [BM000617805!], K [K000231036!]).

Rinorea angolensis Exell (1935: 12). Type: Angola, Cuanza Norte, Dondo, near the Cuanza R., 50 m, 15 Sept. 1931, Gossweiler 9759 (holotype BM [BM000617969!]; isotypes COI [COI00004969!], K [K000231217!], LISC [LISC000523!], US [US00901726!]).

Leaves petiolate; petioles 5 – 40 mm long; lamina 8 – 26 × 2.5 – 14.6 cm; secondary vein pairs 4 – 10; base cuneate to rounded. Inflorescence 2 – 11 cm long; peduncle 0.1 – 1.5 cm long (Fig. 4D).

Fig. 4

Rinorea ilicifolia subsp. spinosa (A – C). A mature fruit (C. Rakotovao 4248; Madagascar); B inflorescence and habit (T. H. Andriamihajarivo 1789; Madagascar); C inflorescence with immature fruit and flowers (G. E. Schatz 3864; Madagascar); D immature fruit of R. ilicifolia subsp. ilicifolia (E. Bidault 2173; Gabon). photos: A C. RAKOTOVAO (MO), B R. LETSARA (CAS), C G. E. SCHATZ (MO), D E. BIDAULT (MO).

distribution. Rinorea ilicifolia subsp. ilicifolia is distributed across Sub-Saharan Africa (Map 1).

Map 1

Distribution of the three subspecies of Rinorea ilicifolia in Africa, Madagascar, and the Comoro Islands.

specimens examined. burundi. Bubanza, Kihanga, ravin Katunguru, 850 m, 6 Nov. 1970, Lewalle 4900 (MO); Bubanza, vallée Katunguru, 900 m, 31 Oct. 1974, Reekmans 3892 (MO [2 sheets]). cameroon. Near Nkolbisson, 7 km W of Yaoundé, 750 m, 27 Dec. 1962, Breteler et al. (P); N’Kolbisson, c. 8 km W of Yaoundé, 650 m, 27 Dec. 1963, de Wilde & Duyfjes-de Wilde 1625 (MO, P, PRE); Nkolbison, 8 km W Yaoundé, au pied la colline de Minlo, Feb – April 1963, Raynal & Raynal 9561 (P, 2 sheets). central african republic. Sangha Economique Prefecture, Ndakan gorilla study area, 02°22'N, 16°09'E, 350 m, 7 Jan. 1988, Harris & Fay 76 (MO); Bamingui-Bangoran, Manovo-Gounda-St. Floris NP, Manovo Creek, 08°13'N, 21°09'E, 590 m, 2 March 1984, Fay 6418 (MO, P). congo (brazzaville). Territoire de Mambasa, Ituri Forest, Epulu, Mont Mbia, 01°25'N, 28°35'E, 750 M, 21 Feb. 2001, Dhego et al. 592 (MO); Mayama, forêt de Bangou, Dec. 1956, Koechlin 3914 or 7262 (P); plateau des cataractes, piste Taba-Mandzakala, région de Kinkala, entre Mandzakala et le pont Voula, 11 Oct. 1968, Sita 2656 (P, 4 sheets). d. r. congo. Forêt de Kinkanga, le long de Inkisi Mbanza-Ngungu, 04°52'S, 15°09'E, 14 June 1978, Breyne 3321 (MO); Equateur, Bikoro, Lac Tumba, Île Elua, 17 Sept. 1945, Léonard 553 (PRE); Haut-Zaire, at Epulu, along the road between Kisangani and Goma, 750 m, 18 Feb. 1986, Linder 3513 (PRE). ethiopia. Kefa A. Region, at the Bebeka Coffee Plantation, S of Mezan Tefari, along the track to Gurrafada, about 24 km W of the coffee plantation H. Q., 06°50'N, 35°15'W, 1050 m, 1 Dec. 1984, Friis et al. 3919 (MO); Illubabor, about 49 km S of Ganbela, along a track leading to the Gila R., 07°50'N, 34°40'W, 500 m, 25 Feb. 1970, de Wilde 6361 (MO). gabon. Ogooué-Ivindo, Chantier S. H. M., Layon 'Z, 00°50'N, 12°05'E, 19 Feb. 1988, Dibata 418 (P); Région Ogooué-Ivindo, 3 km de la route Koumameyong vers Makokou, c. 00°12'N, 11°55'E, 6 Oct. 1983, Floret et al. 1658 (P, 2 sheets); Massif du Chaillu, along road Mimongo-Koulamontou, between Dibandi and Diyanga, 20 – 30 km NE of Mimongo, 01°34'S, 11°44'E, c. 550 m, 27 Nov. 1983, Louis et al. 952 (P, PRE); Woleu-ntem, chantier Oveng, 00°47'S, 11°16'E, 2 May 1986, Louis 2074 (P); Chantier Oveng, c. 25 km WSW of Mintsie, 00°44'N, 11°22'E, 9 Nov. 1986, Reitsma et al. 2584 (MO); Ogooue-Ivindo, Lope Reserve, E of Koumbiane, 00°15'S, 11°40'E, 20 June 1993, White 881 (MO); forêt des Abeilles, 40 km SSW of confluence Ogooue-Ivindo, 00°30'S, 12°02'E, 8 Aug. 1993, Wilks 2722 (PRE, 2 sheets). ghana. W Afao Hills Reserve, 436 m, 12 Feb. 1952, Darko 461 (MO, P); Esen ne Pam Forest Reserve, Oda Road, 26 Nov. 1971, Enti 435 (MO); Agriculture Research Station, Kade, 17 March 1972, Enti 644 (MO, 2 sheets, PRE); Bia NP and Production Reserve, Game and Wildlife Adufua Camp, S 11 km along main logging road, 06°30'30"N, 03°04'00"W, 150 – 190 m, 29 Feb. 1996, Merello et al. 1337 (MO). guinea. Nzerekore, Mt Nimba, 8 Jan. 1949, Adam 3181 (MO, P); Nzérékoré, Koloumba, 24 July 1949, Adam 5770 (P); bord à Kourio, 22 Dec. 1905, Chevalier 14820 (P); Nzérékoré, E of Nimba Mts, banks of Mien R. on or close to reserve border, 07°40.1'N, 08°19.2'W, 540 m, 14 Dec. 2006, Jongkind et al. 7656 (P); Nzérékoré, Lola Prefecture, Nimba Mts, inside the WHS, between Bie village and the mountains, 07°40'42"N, 08°20'06"W, 557 m, 29 Oct. 2012, Jongkind et al. 11630 (P); Région montagneuse du Nimba, April 1950, Schnell 5328 (P). guinea-bissau. Bedanda, 14 Jan. 1962, Pereira 2799 (PRE). ivory coast. 36 km NE of Sassandra, 05°06'N, 05°49'W, 29 Nov. 1968, Breteler 6105 (MO, P); bassin de la moyenne Sassandra, 21 – 23 May 1907, Chevalier 16421 (P); Bouroukrou, chemin de fer km 92, 20 Dec. 1906 – 20 Jan. 1907, Chevalier 16641 (P); sous-préfecture Vavoua, F. C. du Haut-Sassandra, à proximitié de l’ancien chantier de la SIFCI, 07°18'N, 07°01'W, 24 Nov. 1993, Gautier et al. LG2265 (MO); sous-préfecture Bouaflé, P.N. Marahoué E, forêt-galerie de la Marahoué, 07°05'N, 05°53'W, 9 Jan. 1996, Gautier et al. LG2863 (MO). kenya. Utwani Forest, Witu, Dec. 1936, Abdulla 3847 (P); Gongoni Forest, Witu, Oct. 1937, Dale 3801 (P); Kilifi, Chasimba, 03°44'S, 39°42'E, c. 200 – 220 m, 16 Feb. 1977, Faden et al. 77/415 (MO); Kwale Distr., Shimba Hills, Sheldricks's Falls area, 152 m, 2 April 1968, Magogo & Glover 632 (PRE); Kwale, Muhaka Forest, 04°20'S, 39°31'E, 40 m, 19 Feb. 1987, Robertson & Luke 4544 (MO). liberia. Yéképa, route forestière, 1 Feb. 1965, Adam 20793 (P, 2 sheets); Yéképa, Mt Bélé road, 3 Oct. 1975, Adam 29747 (MO, P); Central Province, near the village Diala, c. 18 km E of Tapeta, 31 March 1962, de Wilde & Voorhoeve 3736 (P). mozambique. Cabo Delgado, c. 10 km from Nangade on road to Mueda, 11°12'04"S, 39°38'48"E, 359 m, 23 March 2009, Burrows & Burrows 11318 (BNRH); Nampula, Mossuril, Serra de Mesa, 250 – 300 m, 19 Feb. 1984, de Koning et al. 9747 (MO); Nampula, Eráti, andados 12 km de Namapa para Alua, monte Geovi, 500 m, 8 Jan. 1964, da Torre & Paiva 9888 (MO, P, PRE); Cabo Delgado Prov., hunting concession between Pundanhar and Nangade, 10°56'25.5"S, 39°52'46.5"E, 99 m, 18 Nov. 2009, Goyder et al. 6088 (P). nigeria. Benin, Benin, Okomu Forest Reserve, 3.5 miles S of Nikrawa, 12 Dec. 1947, Brenan 8491 (P); Calabar, Calabar, Akamkpa Rubber Estate, Calabar River Division, 21 March 1959, Latilo 22 (P); Ogun, Omo Forest Reserve, 6 km SE of Etemi, 18 Nov. 1981, Pilz 2667 (MO). sierra leone. Kabala, Mt Loma village, Kruto, 6 Feb. 1966, Adam 23589 (MO). south africa. Zululand [KwaZulu Natal], Hlatikulu Forest, July 1923, Boocock 28 (PRE, 2 sheets]); Zululand [KwaZulu Natal], Ingwavuma, 549 m, s.d., Dutton & Tinley 21 (PRE); Natal, Gwaleweni Forest, 610 m, 19 Oct. 1971, Moll & Nel 5536 (PRE); KwaZulu Natal, Hlatikulu Forest, N of Jozini, c. 200 m along path from forestry office, 27°20'S, 32°00'E, 500 m, 18 Oct. 2002, Nowell 156 (BHO); Zululand [KwaZulu Natal], Ingwavuma Distr., Gwaliweni Forest, 610 m, 10 Aug. 1959, Tinley 474 (PRE). tanzania. Pwani, Rufiji, Kichi Hills, Kungurwe Village, Mkengela Valley, 08°18'S, 38°40'E, 600 m, 22 Sept. 1999, Abeid & Kibure 706 (MO); Kigoma Distr., Mt Livandabe [Lubalisi], 05°58'S, 30°02'E, 1100 m, 6 June 1997, Bidgood et al. 4325 (K, P); Zanzibar, April – May 1848, Boivin s.n. (P); ibid., Sept. 1889, Sacleux 862 (P, 6 sheets); Kwale Distr., Mlinga Peak, E Usambaras, 900 m, 7 March 1953, Drummond & Hemsley 1452 (K); Lindi, Lindi Rural, Milola, Rutamba Ward, former Rutamba village, Litipo Forest Reserve, c. 8 km from Kinyope, 10°02'47"S, 39°28'20"E, 80 m, 7 Nov. 2005, Ezrom et al. 189 (MO); Kagera, Bukoba, Minziro Forest Reserve, Dobero area, N of Nyakabanga, bounded by Kagera R., 01°02'26"S, 31°36'28"E, 1120 m, 16 Oct. 2000, L. Festo 817 (MO); Bukoba Distr., Bushenya, 2 April 1948, J. Ford 316 (K); Pwani, Rufiji, Mchungu Forest, beside the sea at the mouth of the Rufiji Delta, 07°40'S, 39°17'E, 15 m, 2 Aug – 4 Sept. 1990, Frontier-Tanzania 1420B (MO); Tanga, Muheza, Kilulu Hill, 04°46'S, 39°07'E, 200 m, March 1992, Frontier-Tanzania 2700 (MO); Rukwa, Sumbawanga Rural, WCS/SHCP Nawinga Camp, Kafukaka Village land, along Nawinga Stream, (tributary of Loasi R.), 08°17'48"S, 31°08'11"E, 1170 m, 12 Nov. 2009, Gereau et al. 7100 (MO); Pwani, Mafia Island, Rujifi Distr., Uranzi to Kikuni, 9 m, 13 Aug. 1937, Greenway 5081 (PRE); Lindi, Lindi Rural, Mchinga Ward, Kilangala Village, Ruawa Forest Reserve, valley running S from Likonde Ridge, Mpeleganya Valley, 09°43'32"S, 39°32'03"E – 09°44'57"S, 39°33'03"E, 250 – 450 m, 16 Nov. 2003, C. J. Kayombo et al. 4678 (MO); Pwani, Rufiji, [Matumbi Hills, Kiwengoma Forest], near WWF Office, 08°18'57"S, 38°57'39"E, 250 m, 19 Sept. 1997, Kibure 84 (MO); Pwani, Rufiji, Kichi Hills, Mkengela area, 08°18'S, 38°40'E, 600 m, 22 Sept. 1999, Kibure 491 (MO); Pwani, Rufiji, Kichi Hills, near Kungurwe village, 08°17'S, 38°39'E, 600 m, 28 Sept. 1999, Kibure 514 (MO); Kele Hill, Mimziro, 1250 m, 20 April 1994, Longdon 352 (K); Tanga, Muheza, E Usambara Mts, Kwamtili village, 100 m NW of cocoa factory, 04°55'21"S, 38°43'54"E, 100 m, 20 May 2000, Mwangoka 1257 (MO); Pwani, Kisarawe, Kazimzumbwi Forest Reserve, 06°56'41"S, 39°03'14"E, 200 m, 4 June 2001, Mwangoka & Ali 2188 (MO); Kilwa, Mbarawala/Uchungwa Forest, N part of forest along ridge, 09°00'35"S, 39°10'51"E, 359 m, 12 July 2008, Mwangoka et al. 5843 (MO); Tanga, Muheza, E Usambara Mts, W of Kanyani subvillage of Misozwe, 05°02'44"S, 38°43'44"E, 400 m, 4 April 2009, Mwangoka & Semng'ombe 6142 (MO); Tanga, Muheza, Segoma Forest Reserve, S part of forest near Segoma village, 04°59'23"S, 38°46'03"E, 220 m, 29 March 2012, Mwangoka & Walesi 7736 (MO); Lindi, Lindi Rural, Litipo Forest Reserve, Lake Lutamba, c. 40 km W of Lindi, 10°03'S, 39°28'E, 240 m, 4 Nov. 1984, Mwasumbi & Mponda 12643 (MO); Morogoro, Kanga Mts, 90 km N of Morogoro town, Mwasumbi & Munyenyembe 13848 (MO); Pwani, Rufiji, Matumbi Hills, Kiwengoma Forest, 08°19'06"S, 38°56'54"E, 375 m, 10 Oct. 1997, Phillipson et al. 4947 (MO); Tanga, Manga Forest Reserve, Frontier Plot no. 29, 05°01'08"S, 38°45'24"E, 165 m, 31 July 1997, Simon et al. 9 (MO). zimbabwe. Imbeya Estates, Garliso Forest, 19 Jan. 1936, Kleinschmidt 5 (PRE).

habitat. Rinorea ilicifolia subsp. ilicifolia grows in a wide variety of vegetation types, including primary, secondary and degraded humid and seasonally dry forests, gallery forests, semi-deciduous forests, and thickets; alt. near sea level to 1800 m a.s.l. It has been recorded from different substrates such as sand, limestone, basalt, and clay. Observations of plants in the field and from herbarium specimen labels show that subspecies almost always occurs in the understory of forests or thickets

conservation status. With an Extent of Occurrence (EOO) of 1.3 × 10⁷ km², a minimum Area of Occupancy (AOO) of 292 km², and at least 99 recorded localities, Rinorea ilicifolia subsp. ilicifolia is assigned a preliminary conservation assessment of Least Concern [LC] using the IUCN Red List categories and criteria (IUCN 2012).

phenology. This subspecies flowers and fruits between September and April.

vernacular names. The following common names were recorded for subsp. ilicifolia: mtakataka and vitakataka in the Ndengeleko language (O. A. Kibure 491 and 514, respectively), amatodofov, language unknown (Dhego et al. 592), and umkokomane, language unknown (Boocock 28).

notes. In considering the nomenclatural priority between the competing names Alsodeia ilicifolia and Alsodeia spinosa, Tennant (1963) provided compelling evidence that the effective publication of A. ilicifolia antedates A. spinosa (ICBN Recommendation 31A; Turland et al. 2018). Even though the publications containing the protologues of both names bear the printed date of "1868," Tennant (1963) suggested that the effective publication date of A. ilicifolia was shortly before 9 July 1868, while that of A. spinosa was possibly as late as June 1869.

In the protologue of Alsodeia ilicifolia, Oliver (1868) cited three syntypes: Welwitsch s.n. (Angola), Afzelius s.n. (Sierra Leone; specimen not seen), and Brass s.n. (Cape Coast; specimen not seen). Carrisso (1937) first cited the Welwitsch 889 specimens at LISU as type material, followed by Tennant (1963), who identified the same collections as a lectotype, even though he did not examine them. Scrutiny of the nine known specimens of Welwitsch 889 revealed that they are composed of three different gatherings: one from Jan. 1857 (in bud or sterile), one from Feb. 1857 (in bud, fruit, or sterile), and one from May 1857 (in bud). Indeed, Welwitsch was known to merge different gatherings under the same collecting number (Albuquerque et al. 2009). Because Tennant (1963) did not indicate which of the four specimens at LISU he chose as lectotype, the specimen LISU206098 was chosen as the second-step lectotype because it is the most complete, bearing mature fruits, seeds, and some immature flowers (see Article 9.17 of the ICBN; Turland et al. 2018). Three of the isolectotypes were also collected in February 1857, and even though they present different phenologies, they are consistent with the lectotype: M0109597 (bud), LISU206100 (sterile), and PRE0291990-0 (bud). The fourth isolectotype, BM000617803, contains a fruiting branch and a branch in bud, and even though it is not possible to reconstruct which elements on the sheet were collected in Feb. 1857, they are all consistent with the lectotype and are considered here collectively as an isolectotype. Three specimens of Welwitsch 889 are excluded as isolectotypes because they were either collected in Jan. 1857 (BM000617804, LISU206099) or in May 1857 (LISU206101). A fourth specimen, M0109598, is sterile and without a date and is not considered an isolectotype.

1b. Rinorea ilicifolia (Welw. ex Oliv.) Kuntze subsp. spinosa (Boivin ex Tul.) Grey-Wilson (1981: 11). Alsodeia [as Alsodea] spinosa Boivin ex Tul. (Tulasne “1868,” publ. 1869: 307). Rinorea spinosa (Boivin ex Tul.) Baill. (Baillon 1886: 583). Type: Madagascar, Antsiranana Prov., Nossibé [Nosy Be], aux environs de Hellville, June 1847, Boivin 2122bis (lectotype P [P030596!], designated here; isolectotypes K [K000231204!], P [P030597!]).

Leaves petiolate; petioles 2 – 27 mm long; lamina 7 – 26 × 2.4 – 8.3 cm; secondary vein pairs 7 – 14; base cuneate to rounded. Inflorescence 3 – 16 cm long; peduncle 0.1 – 3.2 cm long (Fig. 4A – C).

distribution. The subspecies is distributed in the Comoro Islands and in northern and western Madagascar (Map 1).

specimens examined. comoros. Grande Comore, May 1963, Bosser 18012 (P); Grande Comore, 25 May 1975, Coulon 88 (MO, P); Mohéli, NE centre of island, 14 Aug. 1987, D'Arcy 17615 (MO). madagascar. Antsiranana: Nosy-Be, Lokobe RNI, Lokobe Point, 13°24'29"S, 48°18'48"E, 0 m, 28 Dec. 1996, Antilahimena 356 (K, MO); Ampasindava, forêt de Betsitsika, 12°45'44"S, 48°59'49"E, 275 m, 6 Jan. 2009, Ammann et al. 221 (G); Ambanja, Bemanevika, Bandrakorony, forêt de basse altitude de Bandrakorony, près du ruisseau de Betsitsiky sur la presqu'île Ampasindava, 13°45'36"S, 47°59'15"E, 135 m, 14 Jan. 2009, Bernard et al. 1255 (G); RNI 6, Lokobe, S side of the reserve, study site for the Black Lemur Forest Project, 5 km SE of Hell Ville, Nosy Be, 13°25'S, 48°18'E, 50 m, 18 Sept. 1992, Birkinshaw 161 (G, MO, TAN); Port Leven, March – April 1849, Boivin 2564 (lectoparatype; P); Montagne d'Ambre, July 1953, Bosser 5899 (P); Ambilobe, environs d'Ambatoarana, Dec. 1956, Descoings 1902 (TAN [3 sheets]); Manongarivo RS; Besinkara, forêt en aval d'Ambalafary, sur le chemin d'Anabotoaka, 14°04'S, 48°17'E, 200 m, 24 Sept. 1996, Gautier et al. LG3134 (G, K, P, TAN, TEF, WAG); Andrafiabe, Sahafary, 12°34'49"S, 49°26'55"E, 191 m, 26 July 2004, Guittou et al. 46 (MO, TAN); Ankarana, 10 – 250 m, Dec. 1937 – Jan. 1938, Humbert 18845 (MO, P); Ampasindava, forêt d'Andohankary, 13°38'21"S, 48°04'39"E, 22 Nov. 2007, 30 m, Nusbaumer 2518 (G); Lokobe RNI au SE d'Hell-Ville, Ambanoro, Nossy-Bé, 13°25'S, 48°18'E, 200 m, 20 – 22 May 1998, Rabenantoandro et al. 2 (MO, WAG); Ambolobozobe, Ankonahona, à 1 km au NW du village d'Ambolobozobe, 12°31'00"S, 49°31'00"E, 26 Dec. 2007, Rakotonandrasana et al. 1224 (MO); Ambanja, Bemanevika, Bandrakorony, versant E de la grande rivière de Bandrakorony sur la Péninsule d'Ampasindava, 13°44'50"S, 47°59'26"E, 122 m, 21 Jan. 2009, Rakotovao et al. 4248 (G); Ankarongana, Sahafary, forêt d'Andranomadiro, 12°36'18"S, 49°26'34"E, 258 m, 4 Dec. 2006, Ranaivojaona et al. 1646 (MO); Ambanja, village de Benavony, Bekaka, à 6 km au SE d'Ambanja, 13°43'32"S, 48°28'48"E, 80 m, 15 May 1998, Randrianaivo et al. 228 (G, MO, P); Île Nossi-bé [Nosy Be], s.d., Richard 185 (G, P, 2 sheets); ibid., s.d., Richard 210 (lectoparatype; K, P, 2 sheets); ibid., s.d., Richard 328 (P, TAN); ibid., s.d., Richard 357 (lectoparatype; K, P); without precise locality, s.d., J. M. C. Richard 555 (lectoparatype; P, 2 sheets!); RN 4, Tsaratanana, Marovato, Ambanja, April 1951, RN 2714 (K, MO, P, TAN); RN 6, Nossi-Be, 19 Oct 1951, RN 3011 (P, TAN [2 sheets]); Ambanja, Maromiandra, 6 Oct. 1954, SF 11089 (K, MO, P, TEF); Bekaka, Ambanja, 20 March 1950, SF 3169 (P, TAN, TEF); Nosy Be, Lokobe RNI, village of Ampasindava, 13°24'42"S, 48°18'32"E, 80 – 230 m, 2 Nov. 2006, Wahlert & Rakotonasolo 5 (MO); near the bridge over R. Ramena, on road c. 15 km S of Ambanja, Ambodidmaka, 13°45'S, 48°29'E, 150 m, 8 Nov. 2006, Wahlert & Rakotonasolo 20 (MO); on road from Ambanja to Antanambao, 2 km N of the confluence of the Ramena and Sambirano Rs, 13°45'01"S, 48°45'12"E, 76 m, 11 Nov. 2006, Wahlert & Rakotonasolo 37 (MO); Sahafary forest, 12°34'S, 49°26'E, 176 m, 24 Nov. 2006, Wahlert et al. 58 (MO [2 sheets]); ibid., 12°34'33"S, 49°26'26"E, 157 m, 13 Sept. 2007, Wahlert & Razafimanantsoa 96 (MO); Orangea forest, 12°14'21"S, 49°22'00"E, 35 m, 20 Sept. 2007, Wahlert & Bienaime 102 (MO); RS Manongarivo, Ambahatra, Plateau d'Anketraka Be, 13°56'S, 48°27'E, 200 m, 23 May 2000, Wohlhauser & Andriamalaza 60267 (G, K, MO, P, PRE, WAG); Mahajanga: Besalampy, Marovoay S, Angodoka, Anosibe, 16°55'54"S, 44°43'56"E, 58 m, 11 July 2007, Andriamihajarivo et al.1221 (MO); Melaky, Maintirano, Belitsaky, Ankilimanarivo, forêt de Beanka, lieu dit Antsakoan'ny Betrongo, 18°00'07"S, 44°27'43"E, 210 m, 20 Oct. 2009, Andriamihajarivo et al. 1789 (MO); Antsalova, RN 9, Oct. 1963, Bosser 18111 (P, 2 sheets, TAN); Maromandia, Ankaramy, 19 Dec. 1922, R. Decary 1356 (BM, K, P, TAN); environs de Bekodoka, 3 Nov. 1923, Decary 2361 (P); Namoroka, Soalala, 17 Sept. 1940, Decary 15808 (K, MO, P, WAG); Melaky, Beanka, S de la Kimanambolo, 18°06'57"S, 44°33'43"E, 240 m, 2 Dec. 2012, Gautier et al. LG5919 (MO); entre la mer et Besalampy, 13 Oct. 1968, J.-L. Guillaumet 2256 (P, TAN); Tsingy de Bemaraha N of the Manambolo R., 19°09'S, 44°49'E, 50 m, 1 Dec. 1996, Jongkind et al. 3314 (TAN, WAG, 2 sheets); environs d'Antsalova, 5 km à l'Est de Betivika, RN 9, 18°38'S, 44°43'E, 100 – 200 m, 29 Nov. 1992, Labat et al. 2230 (K, MO, P, TAN); Tsingy du Bemaraha, RN 9, 1932 – 1933, Leandri s.n. (P); Antsalova, 1932 – 1933, Leandri 263 (BM, P, PRE); vers Bevary, E d'Antsalova, lisière E de RN 9, 400 – 500 m, Feb. 1960, Leandri & Saboureau 2907 (P); bord du Manambolo, RN 9, Oct. 1964, Morat 790 (P, TAN); Berizoka [Bertizoka], Oct. 1897, Perrier 355 (P, 3 sheets); Belambo, près de Maevetanana, 1900, Perrier 1409 (P, 2 sheets); Manongarivo, Ambongo, Dec. 1903, Perrier 12117 (P); Kamakama, sur le causse d'Ankara, Nov. 1901, Perrier 12118 (P); Soalala, Andranomavo, Namoroka, bas canyon Ampidiranala, 16°24'46"S, 45°18'23"E, 105 m, 26 Oct. 2016, Rakotovao & Reeb 7084 (MO, P, TAN); Bekopaka, 6 July 1970, Rakotozafy 1005 (TAN); Angonkely, Mitsinjo, 7 July 1977, Rakotozafy 1940A (TAN); ibid., Rakotozafy 1940B (TAN); Ankarafantsika, Ambato-Boeni, Tsaramandroso, 17 Oct. 1950, RN 2008 (MO, P, 2 sheets, TAN, 2 sheets); ibid., RN 2548 (P, TAN, TEF); RN 8, Andranomavo, Soalala, 27 Dec 1952, RN 4917 (P, 2 sheets, TAN, WAG); ibid., 13 Nov 1953, RN 5664 (MO, P, TAN, TEF); ibid., 14 Oct 1956, RN 8153 (P, TEF); Bekopaka, Antsalova, 13 Feb. 1959, RN 10331 (P, TEF); Ambato-Boeni, Tsaramandroso, 28 Oct. 1960, RN 11418 (P); forêt Lomakia, Maintirano, 21 May 1955, SF 14197 (MO, P, TEF); Sahankazo, 16 Dec. 1955, SF 15513 (K, MO, P, TEF); Ambararatakely, Maintirano, 10 July 1956, SF 16343 (K, MO, P, 2 sheets, TEF); ibid., 17 Nov. 1956, SF 16571 (MO, P, TEF); environs d'Andranogidro, 10 July 1957, SF (Capuron) 18034 (P, TEF); forêt de Tsimembo, 50 – 100 m, 24 Feb. 1961, SF 19835 (TEF); Mijamoa, Bevaho, Bekopaka, 16 Oct. 1966, SF 26211 (P, TEF); Ankily, Antsalova, 14 Sept. 1967, SF 26398 (MO, P, TEF); PN Ankarafantsika, village of Ankoririka, c. 15 km N of Tsaramandroso, 16°15'15"S, 47°03'10"E, 330 m, 12 Nov. 2007, Wahlert & Wahlert 120 (MO); Toamasina: Ambodivato, a hill c. 5 km SW of Maroantsetra along coastline of Bay of Antongil, 15°27'25"S, 49°41'41"E, 0 – 30 m, 29 Jan. 1999, G. E. Schatz et al. 3864 (K, MO); à l'Ouest de Nantoraka, au Sud-Ouest de Maroantsetra, 5 Nov. 1963, SF (Capuron) 22857 (K, 2 sheets, MO, 2 sheets, P, TEF). mayotte. À la cascade de Moussa-peré, 1847 – 1850, Boivin 3296 (lectoparatype; BM, P); forest of Sohoa, W coast of island, 12°49'S, 45°06'E, 100 – 200 m, 20 Nov. 2002, Hoffmann et al. 435 (K, MO, P); Sohoa, 12 July 1999, Mas 294 (P); Îlot Bouzi (Chissioua Mbouzi), 12°48'20"S, 45°14'00"E, 26 April 1999, Pignal 1293 (K, MO); Achirongou, 12°42'S, 45°04'E, 24 Sept. 2001, Pignal et al. 1926 (K, MO, P, WAG); Dzoumogné, s.d., Pobéguin 68 (P); Saziley, 12°59'18"S, 45°10'50"E, 10 m, 3 Aug. 2000, Rouhan & Bernier 38 (K, MO, P); Parc Préfectoral Saziley, 13 Sept. 2000, Tarnaud 150 (P); crête au dessus d'Acoua, Madjabalini, 250 m, s.d., Tinguy 804 (P).

habitat. Rinorea ilicifolia subsp. spinosa grows in the understory of primary, secondary, or degraded humid and seasonally dry forests, semi-deciduous forests, and littoral thickets. It grows in sands and in volcanic and calcareous substrates; alt. 0 – c. 500 m a.s.l.

conservation status. In Madagascar, Rinorea ilicifolia subsp. spinosa occurs in a number of sites with protected status: Ampasindava, Ankarafantsika, Ankarana, Bemaraha, Galoko, Lokobe, Manongarivo, and Tsimembo-Manambolomaty. Based on an Extent of Occurrence (EOO) of 1.7 × 10⁵ km², a minimum Area of Occupancy (AOO) of 172 km², and more than 103 recorded localities, many of which are in protected areas, the subspecies is assigned a preliminary conservation assessment of Least Concern [LC] using the IUCN Red List categories and criteria (IUCN 2012).

phenology. The subspecies flowers between September and November and fruits between September and January.

vernacular names. The following common names were recorded for Rinorea ilicifolia subsp. spinosa: antsotsy (in the Sakalava language, Wahlert & Bienaime 102); reampy (Sakalava, Labat et al. 2330, RN 4917, RN 10331, SF 16571, SF 26211); reampilahy (Sakalava, RN 8153); rehampy (Sakalava, SF 14197); sibabe (Sakalava, Humbert 18845); tsibabena (Sakalava, Gautier et al. LG3134, RN 2008, RN 2548, RN 2714, RN 3011); tsibabeny (Sakalava, Wahlert & Wahlert 120; Wohlhauser & Andriamalaza 60267), tsibabini (in the Shibushi language, Rouhan & Bernier 38); and mouho moudrou (in the Shimaoré language, Rouhan & Bernier 38).

notes. In the protologue of Alsodeia spinosa, Tulasne (1868) lists six syntypes: Boivin 2122bis, 2564, and 3296; Richard 210, 357, and 555. The specimen Boivin 2122bis was chosen as the lectotype because it was among the most complete and was represented by three duplicates.

1c. Rinorea ilicifolia Welw. ex Oliv. subsp. amplexicaulis (Grey-Wilson) Wahlert, comb. et stat. nov.

http://www.ipni.org/urn:lsid:ipni.org:names:77205199-1

Rinorea ilicifolia var. amplexicaulis Grey-Wilson, Kew Bull. 36: 118 (1981). Type: Tanzania, Kigoma Distr., Uvinsa [Uvinza], 1128 m, Aug. 1950, A. A. Bullock 3245 (holotype K000231035!; isotypes BR0000008718532 [image!], K000231034!).

Leaves subsessile; petioles to 2 (7) mm long; lamina 13 – 21.2 × 4 – 7.5 cm; secondary vein pairs 9 – 12; base auriculate. Inflorescence 3.5 – 10.5 cm long; peduncle 0.1 – 0.5 cm long.

distribution. The subspecies is distributed in western Burundi (Bubanza Province), and in Tanzania around the southern margins of Lake Victoria (Kagera and Mwanza Regions), and in Rukwa and Morogoro Regions (Map 1).

specimens examined. burundi. Bubanza, Kihanga, Katunguru, 850 m, 8 Feb. 1970, J. Lewalle 4432 (MO). tanzania. Rukwa, Mpanda Distr., Issa R., along stream, Kabamba evergreen forest, 05°25'33"S, 30°35'22"E, 1185 m, 17 Dec. 2002, Abeid et al. 1274 (MO); Rukwa, Mpanda Distr., T4, Misanga Village, Mnyangwa Hill, Ilumba R., 05°40'47"S, 30°55'13"E, 1140 m, 12 Sept. 2005, Abeid et al. 2282 (MO); Kigoma, Kigoma Rural Distr., Gombe Stream NP, Bwavi R., 04°44'10"S, 29°37'23"E, 1100 m, 20 May 1999, Gobbo 344 (BRIT, MO); Ulanga and Iringa Distrs, Udzungwa Mountain NP, 07°43'S, 36°54'E, 650 m, 6 Oct. 2001, Luke et al. 8185 (MO); Morogoro, Morogoro Rural Distr., Mkungwe Forest Reserve, FTEA region T6, 06°53'S, 37°55'E, 450 m, 7 Aug. 2000, Mhoro 33 (MO); Mwanza Distr., Sengerema, Maisome Island, Lake Victoria, 1143 m, Aug. 1958, Proctor 980 (PRE); Lake Province, Bukota Distr., Minziro forest, Sept. 1958, Proctor 987 (PRE); Morogoro, Kilombero, Mwanihana Forest Reserve above Sanje village, 07°52'S, 36°51'E, 950 – 1000 m, 8 Sept. 1984, Thomas 3691 (MO).

habitat. Rinorea ilicifolia subsp. amplexicaulis occurs in a variety of forest types, including submontane, Euphorbia dawei-dominated, dry evergreen, and lowland; alt. 450 – 1185 m. a.s.l. One specimen (Proctor 987) was recorded from a seasonally inundated forest.

conservation status. In Tanzania, Rinorea ilicifolia subsp. amplexicaulis occurs in two sites with protected status: Gombe and Udzungwa Mountains NPs. With an Extent of Occurrence (EOO) of 1.1 × 10⁵ km², a minimum Area of Occupancy (AOO) of 24 km², and nine recorded localities, Rinorea ilicifolia subsp. amplexicaulis is assigned a preliminary conservation assessment of Least Concern [LC] using the IUCN Red List categories and criteria (IUCN 2012).

phenology. Based on herbarium labels, the subspecies is in bud from August through October and is with immature fruit in December; one specimen was in flower in May.

vernacular names. The common name mholo-solela in the Kiha language was recorded for the subspecies (Gobbo 344).

notes. Based on the character differences of shorter petioles and auriculate leaf bases and a mostly non-overlapping geographic distribution with subsp. ilicifolia, we recognise Rinorea ilicifolia var. amplexicaulis at the rank of subspecies. The amount of morphological divergence and geographic isolation, which is greater than would be expected for a taxon at the rank of variety, is further evidenced by the molecular phylogenetic results in Wahlert & Ballard (2012) and Velzen et al. (2015).

Appendix. List of specimens used in morphometric analysis

Rinorea ilicifolia subsp. ilicifolia: Y. S. Abeid & O. A. Kibure 706 (MO); Y. S. Abeid & O. A. Kibure 735 (MO); J.-G. Adam 3181 (MO, P); J.-G. Adam 20793 (P); J.-G. Adam 23589 (MO); J.-G. Adam 29747 (MO); J.-G. Adam 30109 (MO); M. Aubréville 1801 (P); L. Bernardi 8304 (P); L. Bernardi 8414 (P); J. P. M. Brenan 8491 (P); F. J. Breteler 6105 (MO, P); F. B. Dhego et al. 592 (MO); A. Chevalier 14820 (P); A. Chevalier 16641 (P); A. Chevalier 16741 (P); A. Chevalier 16854 (P); A. Chevalier 16921 (P); A. Chevalier 22601 (P); K. O. Darko 461 (MO, P); J. de Koning et al. 9747 (MO); J. J. F. E. de Wilde 6361 (MO); J. J. F. E. de Wilde & A. G. Voorhoeve 3736 (P); W. J. J. O. de Wilde & B. E. E. Duyfjes-de Wilde 1625 (MO); A. A. Enti 435 (MO); A. A. Enti 644 (MO); A. A. Enti 1683 (MO); P. Ezrom et al. 189 (MO); R. B. Faden et al. 77/415 (MO); L. Festo 817 (MO); I. Friis et al. 3919 (MO); Frontier-Tanzania 1420B (MO); Frontier-Tanzania 2700 (MO); L. Gautier et al. LG2265 (MO); L. Gautier et al. LG2863 (MO); D. J. Harris & J. M. Fay 76 (MO); D. J. Harris & J. M. Fay 228 (MO); D. J. Harris & J. M. Fay 534 (MO); C. J. Kayombo et al. 4678 (MO); O. A. Kibure 84 (MO); O. A. Kibure 491 (MO); O. A. Kibure 514 (MO); J. Koechlin 3914 (P); M. G. Latilo 22 (P); J. Lewalle 4900 (MO); Maclaud 182 (P); M. Merello et al. 1337 (MO); M. A. Mwangoka 1257 (MO); M. A. Mwangoka & S. Ali 2188 (MO); L. B. Mwasumbi & P. Mponda 12643 (MO); L. B. Mwasumbi & P. Munyenyembe 13848 (MO); P. B. Phillipson et al. 4947 (MO); G. E. Pilz 2667 (MO); M. Reekmans 3892 (MO [2 sheets]); S. A. Robertson & W. R. Q. Luke 4544 (MO); P. Schnell 5328 (P); V. Simon et al. 9 (MO); A. R. da Torre & J. Paiva 9888 (MO); L. White 881 (MO).

Rinorea ilicifolia subsp. spinosa: L. H. Boivin 2122bis (P); L. H. Boivin 3296 (P); J. M. Bosser 5899 (P); J. M. Bosser 18012 (P); J. M. Bosser 18111 (P [2 sheets]); G. Cremers 2443 (P); P. Coulon 88 (MO); R. Decary 1356 (BM, P); R. Decary 2361 (P); R. Decary 15808 (P); L. Gautier et al. LG3134 (P); J.-L. Guillaumet 2256 (P); P. Hoffmann et al. 435 (MO); H. Humbert 18845 (P); L. Humblot 151 (P); M. Keraudren-Aymonin & G. G. Aymonin 25629 (P); J.-N. Labat et al 2230 (P); J. D. Leandri 263 (P); J. D. Leandri 666 (P); J. D. Leandri 953 (P); J. D. Leandri 1067 (P); J. D. Leandri & P. Saboureau 2907 (P); C. Mas 294 (P); H. Perrier 355 (P); H. Perrier 1409 (P); H. Perrier 12117 (P); H. Perrier 12118 (P); M. Pignal et al. 1926 (MO); C. H. O. Pobéguin 68 (P); R. Randrianaivo et al. 228 (P); J. M. C. Richard 185 (P); J. M. C. Richard 210 (P); J. M. C. Richard 328 (P); J. M. C. Richard 555 (P); RN 2008 (P); RN 2548 (P); RN 2714 (P); RN 3011 (P); RN 4917 (P); RN 5664 (P); RN 8153 (P); RN 10331 (P); RN 11418 (P); G. Rouhan & F. Bernier 38 (MO); SF 3169 (P); SF 14197 (P); SF 15513 (P); SF 16343 (P); SF 16571 (P); SF 18034 (P); SF 26211 (P); SF 26398 (P); L. Tarnaud 150 (P); H. Tinguy 804 (P); S. Wohlhauser & H. Andriamalaza 60267 (P).

Rinorea ilicifolia subsp. amplexicaulis: Y. S. Abeid et al. 1274 (MO); Y. S. Abeid et al. 2282 (MO); G. Gobbo 344 (MO); W. R. Q. Luke et al. 8185 (MO); B. E. Mhoro 33 (MO); D. W. Thomas 3691 (MO).