小花刺薯蓣 xiao hua ci shu yu

Tubers branched; cork brown; transverse section light brown. Stem twining to left, brown (when young) hispidulous, sparsely prickly. Leaves alternate, palmately 3--7-foliolate; petiole sometimes softly prickly; middle leaflet lanceolate or long elliptic, 5--15(--25) × 2--5(--7.5) cm, leathery, hispidulous, margin entire or undulate, apex caudate-acuminate; lateral leaflets obliquely long elliptic-ovate to obliquely lanceolate, smaller than middle leaflet. Inflorescence axis, peduncle, pedicels, and bracts of both sexes all densely hispidulous. Male inflorescence racemose. Male flowers: pedicel ca. 0.5 mm; bract and bracteoles broadly ovate or long acuminate, forming an involucel around perianth; outer perianth lobes ovate, inner ones suboblong; stamens 3, inserted at base of outer perianth lobes; staminodes spatulate, longer than stamens. Female spikes simple. Capsule oblong, 3.5--5 cm, densely fawn woolly, hairs readily rubbed off, base truncate, apex subtruncate to rounded; wings 1--1.5 cm wide. Seeds inserted near apex of capsule; wing pointing toward capsule base. Fl. Jun--Sep, fr. Oct--Jan.

Forests; 200--1300 m. Hainan, ?Yunnan [?Thailand, Vietnam].

The material from Yunnan and Thailand has not been seen by the present authors and may belong to Dioscorea scortechinii var. scortechinii, which is recorded from Malaysia and differs mainly in its larger flowers.