Volume 14 > Part 3 > Year 2019 > Page 425 > Begoniaceae > Begonia

53. Begonia tenasserimensis Phutthai & M.Hugheswfo-1000039777

[§ Parvibegonia], Blumea 62: 26. 2017. Plate XLIV: C–D.

Accepted Name : This is currently accepted.

Description : Monoecious herb, 5–20 cm tall. Stems succulent, glossy, erect, glabrous, pale green or dark red; tubers globose or subglobose, 5–10 mm diam, with numerous fibrous roots. Stipules persistent, pale green, lanceolate, 4 by 3 mm, with sparse glandular hairs. Leaves 3–5 per plant; petiole pale green or maroon, reddish brown when dry, 1–5 cm long; lamina basifixed, succulent, symmetric or subsymmetric, chartaceous when dry, adaxial surface sparsely hirsute, light green, glossy, iridescent, abaxially glabrous and glaucous; palmatifid, 4–7 by 4–8 cm, apex shallowly trilobed, margin dentate or biserrate with short spinose hairs, base truncate or rarely cordate; venation palmate, main veins 3. Inflorescences terminal, 5–9 cm long, a compound dichasium, bisexual, 1–4 times branched with many staminate flowers and 1 pistillate flower per branch on the lowest branch, protandrous; peduncles pale green or dark red, 2–7 cm long, terete, glandular hairs, glossy. Bracts persistent, pale green, lanceolate, 2–3 by 1–2 mm, membranous, glossy, with sparse glandular hairs, apex obtuse, margin entire. Staminate flowers: pedicels 4–5 mm, erect, with glandular hairs; tepals 4, pale magenta, outer 2 suborbicular, 4–6 by 4–5 mm, base rounded, apex obtuse, margin entire, glabrous on both sides; inner 2 lanceolate, 3–4 by 2–3 mm, base obtuse, apex acute, margin entire, glabrous on both sides; androecium zygomorphic, like bunch of bananas, stamens 18–20, yellow, filaments ca 0.5 mm long, anthers oblong ca 1 mm long, apex retuse, dehiscing by slits near the tip, filaments fused in a column. Pistillate flowers: pedicels erect, pale magenta, 3–10 mm long; tepals 5, unequal, pale magenta, outer 2 orbicular, 4–6 by 4–5 mm, apex obtuse, margin entire, base rounded, glabrous on both sides, inner 3 lanceolate or oblong, 3–4 by 2–3 mm, apex acute, margin entire, base obtuse, glabrous on both side; styles 3, fused halfway, yellow, stigmatic band irregularly crescent-shaped; ovary with 3 wings, with glandular hairs, 2-locular, placenta bilamellate. Fruits with persistent tepals, glossy, pale green, pendulous, drying pale brown, 5–6 by 5–10 mm; locule elliptic, 3–4 by 3–5 mm, abaxial wing facing down, slightly larger than the lateral wings, 5–10 mm long. Seeds brown, barrel-shaped, ca 0.3 mm long.

Thailand : PENINSULAR: Ranong (Raksa Warin hot water spring park), Satun (Thung Wa, Than Plio Falls).

Distribution : Myanmar (Tenasserim).

Ecology : In small crevices on eroded limestone rocks amongst numerous pools and small waterfalls in gallery forests, 100–140 m alt. Flowering: July–November; fruiting: November–December.

Notes: The specific epithet ‘tenasserimensis’ is derived from the Tenasserim Range to where the species is endemic.