Scientific name: Begonia sphenantheroides C.-I PengEnglish name: Vietnamese name: Other name:
Herbs monoecious, perennial, erect, 50-150 cm tall. Rhizomes congested, 15-25 mm across, to 9 cm long; erect stem stout, 5-20 mm across, internodes 7-30 cm, glabrous. Stipules caducous, triangular or narrowly so, apex aristate or apiculate, margin entire, glabrous. Leaves alternate, petiole to 20-30 cm long, glabrescent (puberulent when young); leaf blade herbaceous, asymmetric, ovate to broadly ovate, 21-41 cm long, 15-28 cm wide, glabrous or subglabrous, base obliquely cordate, margin irregularly loosely serrulate or denticulate; apex acute or short acuminate; venation 7- or 8- palmate. Inflorescences 2-3 (-7)-flowered, protandrous; peduncle 1-5 cm long, scaberulous; bracts deciduous, narrowly ovate to lanceolate, apex acuminate, margin entire, 0.9-1.8 cm long, subglabrous. Staminate flower: pedicel 0.7-1.5 cm long, scabrous; tepals 4, outer 2 reddish, oblong, ovate or orbicular, 0.8-1.9 cm long, 0.5-1.5 cm wide, abaxially scabrous, inner 2 pinkish, broadly oblanceolate to oblong, 0.5-1.7 cm long, 0.3-0.9 cm wide, glabrous; androecium actinomorphic, subglobose, 0.7 cm across, stamens 70-120, yellow, clavate; filaments 0.7-2 mm long, fused to a short central column; anthers 1.5-1.8 mm long, apex truncate. Carpellate flower: pedicel 1.5-2.2 cm long, scabrous; ovary green, unequally 3-winged, wings red, scabrous, 2-locular; placentae axile, bilamellate; tepals 5, reddish, unequal, elliptic to obovate, 0.9-1.8 cm long, 0.5-1.5 cm wide, apex obtuse, abaxially scabrous; styles 2, ca. 5 mm long, 2-cleft, fused at base, stigmatic band wavy-twisted and spiralled. Capsule nodding, unequally 3-winged, abaxial wing falcate, 5-16 mm tall, ca. 7 mm wide, lateral wings triangular or narrowly so, 3-6 mm tall.
Ecology and distribution
Begonia sphenantheroides C.-I Peng is distributed in limestone areas in Ha Giang Province and Tuyen Quang Province, northeastern Vietnam. This species grow on semishaded to shady, moist, mossy rocky slopes in broadleafed forest.