细茎秋海棠 xi jing qiu hai tang

Begonia tenuicaulis Irmscher, Mitt. Inst. Allg. Bot. Hamburg 10: 543. 1939, not A. Candolle (1859).

Herbs. Rhizome unknown. Stem ca. 40 cm, 4-5 mm in diam., brown hairy. Stipules obliquely triangular-ovate, 9-10 × 4-7 mm, abaxially hirsute on veins, apex acute or obtuse. Petiole 0.9-5 cm, sparsely hirsute; blade ovate, asymmetric, 6-12 × 2.9-7.3 cm, adaxially sparsely hirsute, venation palmate-pinnate, 5-7-veined, more densely so on veins, base cordate, margin serrulate, apex acuminate. Inflorescences pilose; peduncle 3.5-6.5 cm; bracts ovate-oblong or ovate, 10-13 × 7-9 mm, membranous, margin and outside pilose, apex acuminate and long cuspidate. Staminate flowers: pedicel ca. 1.6 cm, hispidulous; tepals 4, outer 2 elliptic-ovate, ca. 1.5 × 1.1 cm, outside hirsute, inner 2 broadly ovate, ca. 8.5 × 6.2 mm, glabrous; stamens numerous; filaments 1-1.4 mm; anthers obovoid-oblong, 0.9-1.2 mm. Pistillate flowers: tepals 5, outside hirsute; ovary oblong, subequally 3-winged, 2-loculed; styles 2, fused at base. Capsule not seen.

● Yunnan (Tengchong).

The description is based on the type gathering.