硬皮豆 ying pi dou

Dolichos uniflorus Lamarck, Encycl. 2: 299. 1786.

Perennial or annual, climbing herbs, to 60 cm tall. Stems clothed with whitish hairs. Stipules lanceolate, 4-8 mm; petiole 0.8-6.8 cm; leaflets 3, thin, ovate-rhomboid, obovate, or ellip­tic, oblique, 1-8 × 0.7-7.8 cm, glabrous or puberulent or rarely velutinous on both surfaces, base rounded, apex rounded or slightly acute. Flowers (1 or)2 or 3(-5) clustered in axils of leaves; peduncle and rachis of inflorescence 0-1.5 cm; bracts linear, ca. 2 mm. Calyx tube ca. 2 mm; lobes triangular-lanceo­late, 3-8 mm. Standard yellow or light yellowish green, with a purple spot in middle, obovate-oblong, 6-12 × 4-7 mm; wings and keel light yellowish green. Legumes linear-oblong, 3-5.5 × 0.4-0.8 cm, puberulent or subglabrous. Seeds light or deep red­dish brown, oblong or orbicular-reniform, 3-4.2 × 2.8-3.5 mm.

Scrub, dry places. S Taiwan (Pingdong) [Bhutan, India, Indonesia, Myanmar, Nepal, Pakistan, Philippines, Sri Lanka; Africa, Australia].

This species is widely cultivated in the tropics as green manure and forage.