5. Begonia arboreta Y. M. Shui, Acta Bot. Yunnan. 24: 307. 2002.
树生秋海棠 shu sheng qiu hai tang
Herbs, deciduous, epiphytic. Tubers subglobose, ca. 1 cm in diam. Leaves solitary; stipules caducous, basal, glabrous; petiole 12-14 cm; blade asymmetric, broadly ovate, 14-15 × 14-17 cm, papery, venation palmate, 3-5-veined, base obliquely cordate, margin irregularly repand-denticulate, distinctly lobed, divided to 3/5 of leaf length; lobes lanceolate, apex acuminate. Inflorescences 10-12 cm tall, terminal, glabrous; bracts caducous, ovate, ca. 0.6 × 0.2 mm. Staminate flowers not seen. Pistillate flowers: pedicel 3-3.3 cm; tepals not seen; ovary glabrous, 3-loculed; placentae axile, bilamellate; styles 3; stigmas 2-cleft. Capsule pendulous, 2-2.4 × 1.2-1.4 cm, subequally 3-winged; abaxial wing slightly larger, apex subtruncate.
● Evergreen broad-leaved forests, on tree trunks; 1700-1900 m. Yunnan (Lüchun).
The description of this epiphytic species is based on a single specimen collected from Lüchun. Begonia arboreta may represent a diminished form of B. garrettii Craib from Thailand and perhaps does not warrant the specific status.