28. Dioscorea bulbifera Linnaeus, Sp. Pl. 2: 1033. 1753.
黄独 huang du
Helmia bulbifera (Linnaeus) Kunth.
Tubers usually solitary, renewed annually, ovoid or pear-shaped, 4--10 cm thick; cork black; roots fibrous. Stem twining to left, glabrous, smooth. Bulblets purplish brown with orbicular spots, globose or ovoid, variable in size, weight to 300 g. Leaves alternate, simple; petiole 2.5--5.5 cm; leaf blade broadly cordate, 8--15(--26) × 2--14(--26) cm, glabrous, margin entire or slightly undulate, apex caudate-acuminate. Male spikes usually clustered in leaf axils or along leafless, axillary shoots, drooping, sometimes branched. Male flowers: solitary, ± contiguous along rachis; bract and bracteole ovate; perianth purple, lobes lanceolate; stamens 6, inserted at base of perianth, filaments nearly as long as anthers. Female spikes often 2 or more together, similar to male ones, 20--30 cm. Female flowers: staminodes 6, ca. 1/4 as long as perianth lobes. Capsule reflexed or drooping, straw-colored, densely purplish dotted, oblong-globose, 1.5--3 cm, glabrous, base and apex rounded; wings 0.25--0.7 cm wide. Seeds inserted near apex of capsule, dark brown; wing pointing toward capsule base, oblong, 1.2--1.6 × ca. 0.5 cm. Fl. Jul--Oct, fr. Aug--Nov.
Mixed forest margins, river banks, valley sides; near sea level to 2300 m. S Anhui, Fujian, S Gansu, Guangdong, Guangxi, Guizhou, Hainan, S Henan, Hubei, Hunan, S Jiangsu, Jiangxi, S Shaanxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [Bhutan, Cambodia, India, Japan, Korea, Myanmar, Thailand, Vietnam; Africa, Oceania].
Dioscorea bulbifera is used medicinally in China, but, unlike in Africa, it is not much used as a food plant.