紫花猪屎豆 zi hua zhu shi dou

Herbs, 1-1.5 m tall. Branches terete, densely pilose. Stip­ules linear to filiform, 5-8 mm, persistent. Leaves simple; peti­ole very short; leaf blade linear-oblong to elliptic-oblanceolate, 5-8 × ca. 2 cm, abaxially sparsely pilose, adaxially glabrous, base attenuate, apex acuminate. Racemes terminal or leaf-opposed, to 15 cm, 1-20-flowered; bracts linear, ca. 1 cm. Brac­teoles inserted at base of calyx tube, similar to bracts. Calyx 2-lipped, 1.5-1.8 cm, densely rusty pilose; abaxial lobes narrow, 2-3 mm wide; adaxial lobes 5-6 mm wide. Corolla yellow or purplish blue, included in calyx; standard obovate, 1-1.2 cm, base with 2 appendages; wings oblong, ± as long as standard; keel rounded with a long twisted beak. Legume cylindric, ca. 1.5 cm, included in or ± as long as calyx, 10-15-seeded, gla­brous. Fl. Aug-Oct, fr. Nov-Feb.

Sparse forests, along trails; 800-1000 m. Yunnan [Bangladesh, Bhutan, India, N Laos].

Indian collections note that the flowers open at dusk and have a sweet scent similar to that of Viola odorata.