Scientific name: Begonia tamdaoensis C.-I PengEnglish name: Vietnamese name: Thu hải đường tam đảoOther name:
Herbs monoecious, perennial, rhizomatous. Rhizomes 4-7 mm across, to 10 cm long; erect stems seen only at anthesis, to 27 cm tall, ca. 4 mm thick, hispid. Stipules narrowly ovate to triangular, ca. 5 mm long, 4 mm wide, margin entire, keeled, apex aristate, arista ca.1 mm long, sparsely hispid. Leaves alternate, petiole to 15 cm long, hispid; leaf blade ovate or elliptic, asymmetric, 8-12 cm long, 5-8 cm wide, glabrous or subglabrous above, tomentose along nerves beneath, base slightly obliquely-cordate, margin very shallowly divided, irregularly serrulate and ciliate; apex acute to acuminate; venation palmate-pinnate. Inflorescences axillary, protandrous, to 25 cm long, with 4-12 flowers; peduncles 5-21 cm long, hispid; bracts persistent, lanceolate to triangular, apex acuminate, to 5 mm long, margin sparsely fimbriate. Staminate flower: pedicel 1.2-2.3 (-2.8) cm long, glandular-hispid; tepals 4, pink, apex obtuse, outer 2 ovate or narrowly so, 0.8-2 cm long, 0.4-1.2 cm wide, hispid abaxially, inner 2 narrowly oblong or oblanceolate, 0.8-1.8 cm long, 2-6 mm wide; androecium zygomorphic, stamens 12-35, yellow, clavate; filaments 0.5-2.3 mm long, fused at base, anthers 1.6—1.8 mm long. Carpellate flower: pedicel 1.5-2.1 cm long, glandular- pilose; ovary unequally 3-winged, glandular-hispid, 2-locular; placentae axile, bilamellate; tepals 5, pink, unequal, oblanceolate, oblong or ovate, 1.5-1.8 cm long, 0.4-1.3 cm wide, hispid outside, apex obtuse; styles 3, fused at base, 2-cleft, stigmas in a spiralled band around style apex. Capsule nodding, unequally 3-winged, abaxial wing ligulate or falcate, 11-19 mm tall, lateral wing ca. 3 mm tall.
Ecology & Distribution
Known only from Tam Dao, Vinh Phuc Province, Vietnam (Fig. 3). On rock face on roadside slope, in broadleaf forest, elev. 1050 m, locally common.