土圞儿 tu luan er

Apios cavaleriei H. Léveillé.

Herbs, twining. Root tuber spherical or ovoid. Stems slender, sparsely hirsute. Leaves pinnately 3-7-foliolate, 10-25 cm; stipules linear-triangular, to 4 mm, very inconspicuous; peti­ole 3-6.6 cm, glabrous; stipels inconspicuous; petiolules some­times hairy; leaflets ovate or rhomboid-ovate, 3-7.5 × 1.5-4 cm, papery, abaxially sparsely hirsute, adaxially glabrous, base broadly cuneate or rounded, apex acute, mucronate. Raceme axillary, 6-26 cm; bracts and bracteoles minute, lanceolate, cili­ate, deciduous. Calyx bowl-like, shallowly 2-lipped. Corolla yellowish green or light green; standard orbicular, 1-1.5 cm; wings almost half as long as standard; keels much longer than standard, curled into semicircle. Ovary sparsely shortly hairy; style coiled, glabrous. Legume light brown, ca. 8 × 0.6 cm, gla­brous, compressed. Fl. Jun-Aug, fr. Sep-Oct.

Mountain slopes; 300-1000 m. Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan, Zhejiang [Japan].

The root tuber is a source of starch, sometimes used to make alcohol.