Synonym: Begonia serratifolia.
Region: Panama, Colombia, Venezuela.
Habitat: tropical moist forest; rare, in the forest.
Botany: monoecious, erect or scandent, perennial herb, to 1 m long; stems woody at base, glabrous; leaves strongly asymmetrical, lanceolate to elliptic-lanceolate, somewhat acuminate, inequilateral at base, one side cuneate, the other rounded, 5-9 cm long, 1.5-4 cm wide, membranaceous, glabrous, margins doubly crenate-serrate, ciliate; stipules oblong to ovate, acuminate, ca 8 mm long; petioles 2-20 mm long; inflorescence in cymes, dichotomously branched; flowers pinkish-white, bracts often deciduous, ovate, ca 5 mm long; staminate tepals 4, unequal, outer 2 ovate, 8-15 mm long, inner 2 elliptic to lanceolate, about half as long as outer; stamens numerous; pistillate tepals 5, subequal, elliptic, to 10 mm long; styles 3, bipartite; stigmas branched and finally spiraled; fruit develop quickly, capsules elliptic to oblanceolate, 3-winged, the wings very unequal, the largest triangular, ascending, 1.5 cm wide; seeds very numerous, elliptic, 0.3 mm long.