山黑豆 shan hei dou

Herbs climbing and twining. Stems slender, 1-3 m, usu­ally glabrous. Stipules small, linear-lanceolate, 2-4 mm, 3-veined; petiole slender, 3-7 cm, glabrous; petiolules 2-3 mm, glabrous; stipels setiform, ca. 1 mm; leaflets membranous, tri­angular or ovate-triangular, usually 3-6 × 2.3-3.5 cm, both sur­faces usually glabrous or sparsely hirsute abaxially, base trun­cate or rounded, apex ± rounded, sometimes slightly emargi­nate with mucro; lateral leaflets slightly smaller, base slightly oblique. Raceme axillary, slender, 1-4 cm, usually glabrous; pe­duncle short; bracts and bracteoles small. Flowers 1.2-2 cm; pedicel 1-3 mm. Calyx ca. 6 mm, glabrous. Corolla yellow or light yellow; standard elliptic to slightly obovate; wings and keels almost elliptic, slightly curved, slightly shorter than stan­dard, with long claws, with a small auricle at base of one side. Ovary linear-oblanceolate, glabrous; ovules 3-5; style slender, glabrous. Legume oblanceolate to lanceolate-elliptic, ca. 4 × 0.9 cm, slightly inflated, base acuminate, apex with beak. Seeds usually 2-5, blue, compressed, globose, 4-6 mm in diam. Fl. Aug-Sep, fr. Oct-Nov.

Mountain roadsides, wet places; 300-1000(-2300) m. Anhui, Fu­jian, Guangdong, Henan, Hubei, Jiangxi, Shaanxi, Zhejiang [Japan].