山薯 shan shu

Dioscorea hainanensis Prain & Burkill, Bull. Misc. Inform. Kew 1936: 494. 1936.

Tubers vertical, cylindric; cork drying brown, persistent; transverse section white. Stem twining to right, glabrous, prickly at base. Leaves alternate basally on stem, opposite distally on stem, simple; leaf blade elliptic-ovate to broadly lanceolate, 4--14(--17) × 1.5--8(--13) cm, papery, glabrous, basal veins 5 or 7, outermost ones near margin, base sagittate or hastate to deeply cordate or rounded with basal lobes slightly spreading, apex acuminate or caudate. Male spikes 2--4 together, 1.5--3 cm, in axillary panicles to 40 cm; rachis zigzagged. Male flowers: outer perianth lobes broadly ovate, 1.5--2 mm, inner ones obovate, narrower but thicker than outer; stamens 6. Female spike often solitary, to 25 cm in fruit. Capsule not reflexed, oblate, 1.5--3 cm; wings 1--2.2 cm wide. Seeds inserted near middle of capsule, winged all round. Fl. Oct--Jan, fr. Dec--Jan.

* Mixed forests, mountain slopes, valleys, along rivers, roadsides; near sea level to 1200 m. Fujian, Guangdong, Guangxi, S Hunan, S Zhejiang.