Begonia tripurensis Dixit, B. Datta & D. Borah, sp. nov.
Creators: name: Bora, Dixit
name: Borah, Dipankar
name: Hughes, Mark
name: Das, Sani
name: Banik, Biplab
name: Debbarma, Smita
name: Datta, Badal Kumar
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Cucurbitales
Begoniaceae
Begonia
Begonia tripurensis

description: Begonia tripurensis Dixit, B.Datta & D.Borah sp. nov.
Type:― INDIA. Tripura: Gomati, Near Dumboor Lake, N 23° 25’ 34.97”, E 91° 49’ 09.042”, 115 m a.s.l, 10 January 2023, Dixit Bora & Sani Das 4315 (holotype CAL!; isotype ASSAM!).
Diagnosis:― Begonia tripurensis is similar to B. scintillans Dunn (1920:111) in its rhizomatous habit, villous rhizome, stipules hairy abaxially, lamina ovate with reddish hairs on the lower side, inflorescence axillary, staminate flower with four tepals, capsules with three wings with central one larger, but B. tripurensis differs chiefly in being larger at 20–30 cm tall (vs. 7–15 cm), having deciduous stipules 2–2.1 × 0.7–0.8 cm, abaxial side with red stiff hairs (vs. persistent stipules, 6–11 × 4–6 mm, villose abaxially), lower surface of lamina dense reddish hirsute (vs. lower surface red tomentose), outer tepals of staminate flower with acute apex (vs. rounded), capsule with red stiff hairs (vs. red villose hairs), apex of longest wing acuminate, size 15–17 × 5–6 mm (vs. apex rounded, size 5 × 4–6 mm). It is also similar to B. chindwinensis (Maw et al., 2021: 226) and B. thomsonii, for which a comparison table is provided below (Table 1).
Monoecious rhizomatous herb, perennial, creeping, 20–30 cm high. Rhizomes short, 3–4 × 1–1.5 cm, internodes 1–1.5 cm on the rhizome, erect stems only seen during flowering, elongating to ca. 10 cm on flowering internodes, reddish, minutely villous. Stipules narrowly triangular, 20–21 × 7–8 mm, adaxial side sub-glabrous, abaxial side with dense transparent hirsute. Leaves 6 or 7; petiole 10–12 × 0.5–0.7 cm, densely pilose; lamina 7–10 × 4–8 cm, ovate to broadly ovate, basifixed, base cordate, basal lobes overlapping when young, becoming non-overlapping when mature, asymmetric, adaxially sparsely pilose, light green, abaxially densely reddish hirsute; venation basally palmate 8–9, prominently raised on upper surface; margin repand to serrate, ciliate; apex acute to attenuate. Cymes axillary, few, sub-pendulous, pilose, primary peduncle 5–10 cm long, secondary 1–3 cm long. Bracts caducous, subulate, 2–3 × 1–2 mm, hirsute. Staminate flowers 5–7, pedicel 1.5–2 cm long, pubescent, tepals 4, white to pink, outer tepals broadly ovate to orbicular, 10–12 × 10–11 mm, pinkish hirsute on the outer surface, apex acute, inner 2 tepals elliptic to ovate, 5–8 × 2–3 mm, glabrous, apex obtuse; stamens 40–60, ca. 2 mm long, sub-equal, anthers obovate, apex emarginate, basifixed, lower anthers sub-sessile, central anthers on a filament up to 2 mm long. Pistillate flowers 2 or 3, pedicel 1–1.2 cm long; tepals 5, pinkish-white, 4 outermost sub-equal, hirsute on the outer surface, ovate, 9–10 × 4–5 mm, inner one smaller, glabrous, elliptic to ovate, 6–7 × 3–4 mm, apex rounded; ovary 5–7 × 8–10 mm excluding wings, reddish, sparsely hirsute locules 2; styles 2, 5–7 mm long, fused at the base, spiraled; wings 3, adaxial wing oblong, 6–8 × 3–5 mm, apex acuminate, lateral wings 2, underdeveloped. Capsule sub-pendulous, 15–17 × 12–14 mm, adaxial wing larger 15–20 × 5–6 mm, lateral wings 2, 2–3 × 5–6 mm.
Flowering and Fruiting:― January March
Habitat and ecology:― The plants were found on a cliff, with a total of four sub populations of 8–15 individuals separated by at least 300 meters. They were found growing with Lycopodiella cernua (L.) Pic.Serm., Oplismenus hirtellus (L.) P.Beauv., Lygodium flexuosum (L.) Sw., Thysanolaena latifolia (Roxb. ex Hornem.) Honda, Colocasia sp., etc.
Distribution:― Only known from India (Tirthamukh, Gomati district, Tripura).
Etymology:― The specific epithet refers to the state Tripura, in North East India from where the plants of type specimen were collected.
Additional specimens examined (paratypes):― INDIA. Tripura: Gomati, Near Dumboor Lake, N 23° 25’ 28.52”, E 91° 49’ 19.99”, 121 m a.s.l, 20 January 2023, Dixit Bora & Sani Das 4320; ibid., N 23° 25’ 34.56”, E 91° 49’ 09.10”, 119 m a.s.l., 25th March 2023, Dixit Bora & Sani Das 4321 (Herbarium of Tripura University); ibid., N 23° 25’ 32.18”, E 91° 49’ 02.56”, 112 m a.s.l., 20th May 2023, Dixit Bora & Sani Das 4322 (Herbarium of Tripura University).
Conservation status:― After several investigations throughout the Gomati district of Tripura, only four populations each with 8–15 individuals were found within a 500 meter area. However, the similar habitats exist in other regions of the state where the species may occur. In view of the limited fieldwork presently possible, an assessment of Data Deficient (DD) is suitable for this species due to lack of knowledge on its full distribution (IUCN Standards and Petitions Committee, 2022).
description: Published as part of Bora, Dixit, Borah, Dipankar, Hughes, Mark, Das, Sani, Banik, Biplab, Debbarma, Smita & Datta, Badal Kumar, 2024, Begonia tripurensis (Begoniaceae, sect. Platycentrum), a new species from Tripura, Northeast India, pp. 177-182 in Phytotaxa 640 (2) on pages 178-180, DOI: 10.11646/phytotaxa.640.2.6, http://zenodo.org/record/13213582