细柄薯蓣 xi bing shu yu

Dioscorea maximowiczii Uline ex R. Knuth.

Rhizome horizontal, cylindric, 0.6--1.5 cm thick, with obvious nodes and internodes. Stem twining to left, glabrous, smooth. Leaves alternate, simple; petiole 3--5 cm; leaf blade drying green, triangular, 5--10(--13) × 2.5--7(--11) cm, papery, glabrous, base broadly cordate, margin entire or slightly undulate, apex acuminate or caudate. Male spike solitary, rarely paired, 7--18 cm. Male flowers: solitary or paired; pedicel 1.5--8 mm; perianth pale yellow, saucer-shaped to slightly reflexed, lobes suboblanceolate, apex obtuse or rounded; stamens 6, inserted at base of perianth, anthers extrorse, 3 with forked connectives and 3 without. Female spikes to 8 cm, few flowered. Female flowers: staminodes filiform. Capsule pale yellow-brown, shiny, 2--2.5 cm, base rounded, apex truncate; wings 1.2--1.5 cm wide. Seeds inserted near middle of capsule, winged all round.

Forests; 800--1100 m. S Anhui, Fujian, N Guangdong, S Hunan, Jiangxi, Zhejiang [Japan, Korea].