83. Centrosema (Candolle) Bentham, Comm. Legum. Gen. 53. 1837.
距瓣豆属 ju ban dou shu
Authors: Ren Sa & Michael G. Gilbert
Clitoria sect. Centrosema Candolle, Prodr. 2: 234. 1825.
Shrubs or herbs, procumbent or climbing. Leaves pinnately 3(-7)-foliolate; stipules striate, basifixed, persistent; stipels small. Inflorescence axillary, clustered to racemose, 1- to many flowered; bracts similar in shape to stipules; bracteoles 2, adnate to calyx, persistent, striate, larger than bracts. Calyx shortly campanulate, 5-lobed; lobes unequal. Corolla white, purple, red, or blue, longer than calyx; standard ± circular, abaxially hairy, base clawed, with short abaxial spur above claw. Stamens diadelphous; vexillary stamen free; anthers uniform. Ovary sessile; ovules many; style compressed, spatulate at apex, pubescent or bearded at apex; stigma terminal. Legume linear, dehiscent, compressed, filled between seeds. Seeds to 20, oblong or globose; hilum linear to narrowly elliptic; strophiole small or absent.
About 45 species: worldwide but mostly in the New World; one (or possibly two) species (introduced) in China.