无翅参薯 wu chi shen shu

Tubers ovoid or cylindric; cork drying brown; transverse section white. Stem twining to right, green or purplish red, glabrous. Leaves alternate basally on stem, opposite distally on stem, simple; leaf blade abaxially purplish red along veins, ovate to long elliptic-ovate, 6--16 × 4--14 cm, glabrous, basal veins 7 or 9, base sagittate or hastate to cordate with basal lobes bluntly angular, apex acute, acuminate, or caudate. Male spikes solitary or a few together, 2--3 cm, borne along paniclelike, lateral branches to 30 cm; rachis obviously zigzagged. Male flowers: sessile; outer perianth lobes elliptic-ovate, apex obtuse, inner ones spatulate; stamens 6. Female spikes solitary or paired. Female flowers: outer perianth lobes broadly ovate, inner ones elliptic. Capsule not reflexed, oblate, 1.5--2.5 cm; wings 1.7--2.3 cm wide. Seeds inserted near middle of capsule, winged all round.

Mixed forests, broad-leaved forests, bamboo forests, mountain slopes, valleys, roadsides; 1000--2400 m. Guangdong, Guangxi, Guizhou, Sichuan, Yunnan [Thailand, Vietnam].