Begonia acetosella Craib

Herbs, dioecious, erect, to 2 m tall. Rhizomes short, stout. Stems branching twice or more. Leaves cauline; stipules deciduous, lanceolate, 1-1.3 × ca. 3.5 mm; petiole 2.7(-10) cm, glabrous or pubescent; blade oblong, ovate-lanceolate, or oblong-lanceolate, asymmetric, 10-14(-27) × 3-4.5(-8) cm, glabrous, subglabrous, or pubescent, venation palmate-pinnate, 5- to 7-veined, base obliquely cordate, margin undivided, shallowly and remotely serrate, apex acuminate or acute. Inflorescences much reduced; bracts ovate-lanceolate, 1-1.5 cm, apex acuminate. Staminate flowers: pedicel ca. 1.2 cm; tepals 4, white or pinkish, glabrous, outer 2 obovate to oblate, ca. 1.2 × 1 cm, inner 2 lanceolate to oblong, 13-15 × ca. 7 mm; stamens numerous; filaments free; anthers oblong. Pistillate flowers: pedicel 5-10 mm; ovary obovoid, glabrous, (3 or)4-loculed; placentae axile, bilamellate; tepals 4, white or pinkish, glabrous, outer 2 oblate-orbicular, ca. 1 × 1 cm, inner 2 oblong, ca. 10 × 7 mm; styles (3 or)4, fused at base; stigmas 2-cleft, spiraled. Fruit berrylike, pendulous, (3 or)4-horned. Fl. Apr-May, fr. May. 2n = 20, 22*.

SE Xizang, S Yunnan [Laos, Myanmar, Thailand, Vietnam].

Moist shaded environments in evergreen broad-leaved forests; 500-1800 m.