20. Begonia ceratocarpa S. H. Huang & Y. M. Shui, Acta Bot. Yunnan. 21: 13. 1999.
角果秋海棠 jiao guo qiu hai tang
Herbs, acaulescent, rhizomatous. Rhizomes 5-15 mm in diam. Leaves all basal; stipules ovate-oblong, 1.8-2.5 × 0.9-1.1 cm, margin subentire, ciliate, apex acuminate; petiole to 30 cm, densely appressed pubescent; blade ovate-oblong, asymmetric, 14-23 × 7-12 cm, abaxially villous, adaxially glabrous, venation palmate-pinnate, base oblique, cordate, margin slightly repand and slightly crenate, undivided or very shallowly divided into 2 or 3 lobes, apex acuminate. Inflorescences axillary, racemose at base, to 10(-20) cm tall, glabrous or remotely pubescent; peduncle 5-6 cm; bracts lanceolate, 7-8 × 2-3 mm, abaxially pilose, apex acuminate. Staminate flowers: pedicel 7-12 mm, pilose; tepals 4, pink, glabrous or minutely appressed pubescent, outer 2 broadly ovate, 10-17 × 8-12 mm, inner 2 obovate-lanceolate, ca. 12 × 4-5 mm; stamens 17 or 18; filaments 2-3.4 mm, free; anthers obovoid-oblong, 1.6-2 mm, apex obtuse. Pistillate flowers: pedicel 5-7 mm; tepals 5, pink, glabrous or minutely appressed pubescent, unequal, largest broadly obovate, 9-15 × 7-10 mm, smallest oblong, 5-12 × 3-6 mm; ovary minutely appressed pubescent, 3-loculed; placentae axile, bilamellate; styles 3, fused to halfway; stigmas 2-cleft, spiraled. Fruit berrylike, rhomboid, indehiscent, 3-horned. 2n = 20*.
Broad-leaved forests by streams; 300-400 m. Yunnan (Hekou) [Vietnam].
This species is similar to Begonia balansana Gagnepain, which is endemic to N Vietnam, but differs in that the plants are monoecious and the ovary is 3-loculed.