Description from Flora of China
Herbs annual or perennial. Stem often climbing by means of tendrils, terete, glabrous. Leaves paripinnate with rachis terminating in a tendril; stipules leaflike, cordate, larger than leaflets (to 10 cm); leaflets 1-3-paired, ovate to elliptic, margin entire or dentate. Inflorescence a 1- to many flowered raceme. Calyx campanulate; teeth ± leaflike, at least 2 teeth less than 2 × as long as tube. Corolla white or otherwise colored; standard obovate. Stamens diadelphous; staminal tube not oblique at apex; filaments distally slightly dilated. Ovary subsessile; ovules many; style curved inward, distally dilated and margin recurved forming a laterally compressed body, longitudinally grooved, hairy on upper side. Legume long elliptic, inflated, apex acute. Seeds many, spheroid.
Two or three species: Mediterranean region to SW Asia, one species cultivated in temperate regions worldwide, including China.
(Authors: Bao Bojian (包伯坚); Nicholas J. Turland)