Introduction

The genus Glochidion J.R.Forst. & G.Forst., belonging to the tribe Phyllantheae was one of the large genera of the family Phyllanthaceae with about 320 species and distributed mainly in tropical Asia to Northern Australia & Polynesia, with a few species in Madagascar and tropical America (Chakrabarty and Gangopadhyay 1995; Hoffmann et al. 2006; Chakrabarty and Balakrishnan 2018). In India, it comprises of 22 species and 13 varieties (Balakrishnan et al. 2012; Chakrabarty and Balakrishnan 2018). A total of 16 species of the genus were reported by Kanjilal et al. (1940) in “Flora of Assam” from the erstwhile Assam. The name Glochidion was first given by J. R. Forster and G. Forster in ‘Characteres Generum Plantarum’ (1776) and the generic word “Glochidion” came from the Greek word “Glochis” which signifies the extension of anther connectives of a female flower (Chakrabarty and Gangopadhyay 1995). Members of Glochidion are found predominantly in grasslands, evergreen forests, sal forests, deciduous forests, subtropical forests, hilly places, swampy areas along stream sides, and roadside areas. They are generally shrub or large trees, drooping branched having either glabrous or hairy plant bodies, inflorescences exhibit axillary to supra-axillary with lobed and unlobed capsules. The genus comprises of many species and varieties and has been popularly known for its medicinal value in India (Chakrabarty and Balakrishnan 2018).

While exploring the field survey, a voucher specimen of the member Glochidion was collected. The present communication reported the presence of Glochidion zeylanicum var. paucicarpum Chakrab. & N.P. Balakr. in Assam for the first time. The specimen was distributed in Andaman and Nicobar Island, India and it was reported as an endemic variety of Glochidion zeylanicum (Gaertn.) A. Juss., also unreported in Flora of Assam (Kanjilal et al. 1940; Chakrabarty and Balakrishnan 2018). The present communication provides the evaluation of the morphological characteristics, habitat and ecology, phenology, and threat status along with the notes and photographs.

Fig. 1
figure 1

Distribution record of Glochidion zeylanicum var. paucicarpum in Assam

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Materials and methods

A thorough field survey was conducted in different places of Assam including some national parks, reserve forests, and wildlife sanctuaries likewise, a field survey was carried out between May 2022 and January 2023 in the forest area of Owabari village, near the Ultapani Forest Range of Kokrajhar district, Assam. Before conducting the field survey, approval was taken from Assam State Biodiversity Board (ASBB) and PCCF Wildlife Warden, Panjabari, Assam. During the survey, ethnobotanical uses of the specimen were also gathered by interrogating local peoples of the study area. Under a Leica EZ4W stereo-zoom microscope and simple microscope, morphological evaluation of the specimen was carried out. Following a detailed review of herbarium sheets available at the herbaria (CAL), the specimens were further identified with the aid of relevant literature (Chakrabarty and Balakrishnan 2004, 2018; Balakrishnan and Chakrabarty 2007). Literature on the taxonomy of Glochidion, revision work on Glochidion, and information on the endemic status of the taxa were gathered from standard databases such as ResearchGate, Scopus, Academia edu, PubMed, and Google Scholar published from 1984 to 2020 using the keywords such as Glochidion, Taxonomy of Glochidion, New record of Glochidion and Glochidion zeylanicum. Information on geographical distributions was compiled from regional floras, original species descriptions, and databases (GBIF, IPNI, Plants of the World Online, and WFO plant list). Scientific names and synonyms were validated through www.plantsoftheworldonline.org. A voucher specimen of the collected taxa was prepared by following the standard methods of Jain and Rao (1977) and Clark (1986) and the specimen was deposited at Bodoland University Botanical Herbarium (BUBH), Bodoland University, Kokrajhar, Assam.

Fig. 2
figure 2

Glochidion zeylanicum var. paucicarpum Chakrab. & N.P. Balakr. a: habit character; b: inflorescence; c-e: close view of leaves (upper and lower surface); f: female flower; g: sepals; h: pedicillate of female flower; i: a capsule; j: t.s. of a capsule; k: seeds

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Results

After careful taxonomic evaluation and scrutiny of authentic literature (Chakrabarty and Balakrishnan 2004, 2018; Balakrishnan and Chakrabarty 2007) and critical examination of the herbarium specimens available at CAL, the specimen was identified as Glochidion zeylanicum var. paucicarpum Chakrab. & N.P. Balakr. which is a new distributional record to Assam (Fig. 1).

Taxonomic treatment

Glochidion zeylanicum var. paucicarpum

Chakrab. & N.P. Balakr. in J. Econ. Taxon. Bot. 28: 123, t. 1. 2004; N.P. Balakr. & T. Chakr., Fam. Euph. India 354. 2007; T. Chakr. & N.P. Balakr., Indo-Bur. Phy. 252. 2018 (Fig. 2).

Monoecious; shrub or medium size tree, branched, branchlets dark green to brown, entirely pubescent; bark dark brown outside, whitish yellow or brownish red inside. Leaves alternate, simple, smooth, densely pubescent on the lower surface, coriaceous, thick, broad, elliptic, ovate, lanceolate, 6–22 × 4–8 cm, acute at apex, obtuse, truncate, symmetric rarely oblique, rounded at base, petiolate, stipulate, green, margin entire, veins reticulate, lateral nerves 6–10 per side; petioles 0.9–1 cm long; stipules triangular, 0.4 cm long. Inflorescences supra-axillary, few-flowered, pedunculate. Male flowers white, pubescent. Female flowers single, supra-axillary, pedicellate, 1 cm long, green, brown; sepals 3, 0.3–0.5 cm; ovary subglobose, 4–8 locular, 0.9–1 cm long, pubescent, yellow-green; style persistent, columnar, conical, 0.1 cm, green, brown, tomentose. Capsules subglobose, pedicellate, tomentose, unlobed, bilobulate, 8 locular, 1.5–2 × 1–1.5 cm, single in each axil, green or light yellow-green at young, green and slightly purplish red at the top at mature; seeds orange to red.

Flowering

December – March.

Fruiting

April – August.

Habitat and Ecology

The specimen was found in semi-evergreen and moist deciduous forests, primary forests, swampy areas, and streamside areas at about 76 m altitude. All the varieties of Glochidion zeylanicum viz., G. zeylanicum var. zeylanicum, G. zeylanicum var. arborescens, G. zeylanicum var. tomentosum also were found growing a sufficient amount in the area. The locality usually receives heavy rainfall from April to September. The soil type of the locality is usually alluvial soil exhibiting sandy loam to clay loam.

Distribution

India (Andaman & Nicobar Islands) — endemic, Assam (reported in the present study).

Specimen Examined: INDIA. ASSAM: Kokrajhar District, Owabari, Daolur dwisa, near Ultapani Forest Range (N 26º37.131’ E 090º18.784’), 29 May 2022, P. Brahma 010 (BUBH); Andaman & Nicobar Islands, Middle Andaman Island, Jarawa Reserve, ATR, 1 km before Dhani Nala, 17 Aug. 2002, T. Chakrabarty 19,160 A (holotype CAL!, CAL0000022754: image!) 19,160 B, C, D, E (isotypes CAL!, CAL0000022739: image!, CAL0000022740: image!, CAL0000022741: image!, CAL0000022738: image!).

Uses

The powder of leaves and young shoots are mixed with water and used in the treatment of skin diseases. Branches are also used as firewood by the Bodo community of the study area.

Notes

This is the first report of this specimen from Assam including North-East India. G. zeylanicum has a total of four varieties including itself viz., G. zeylanicum var. zeylanicum, G. zeylanicum var. arborescens, G. zeylanicum var. tomentosum and G. zeylanicum var. paucicarpum. The specimen closely approaches G. zeylanicum var. tomentosum by its hairy plant body and the similarity of their morphological structure of the capsule but differs by its individual capsule in each axil and single female inflorescence in the axil.

Threat status

Only 10–15 individuals were observed in the locality during the survey. Moreover, the majority of its habitat disturbances are caused by anthropogenic activities (Fig. 3), such as intensive deforestation, cutting of trees for the purpose of catching fish by the villagers of the locality, and ensuing deterioration. G. zeylanicum var. paucicarpum has not yet been included in the IUCN Red List and red data book of Indian Plants (Nayer and Sastry 1987-90). But based on the IUCN red list criteria (IUCN 2022) we suggest the specimen in the endangered category.

Fig. 3
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Effect of anthropogenic activities in the study site (Fig. a & b): habitat disturbances (fish catching method by the villagers & deforestation)

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Conclusion

Chakrabarty and Balakrishnan first collected G. zeylanicum var. paucicarpum from Andaman & Nicobar Islands Middle Andaman Island, Jarawa Reserve and reported it as endemic to this area. But the present study confirms the G. zeylanicum var. paucicarpum as a new distributional record to Assam including northeast India as well as a new addition to the flora of Assam. G. zeylanicum itself is a complicating species that exhibits vast variations including G. zeylanicum var. paucicarpum throughout its area of distribution and it requires further consequential population studies.