Erect or twining annual herb, branches spreading from the base, clothed with fine, long, deciduous, reflexed, greyish brown hairs; petiole about 5-21 cm long; stipules peltate, ovate, hairy; leaves 3-foliolate; leaflets membranous, not gland dotted, terminal one elliptic-ovate, glabrous or pilose, acute or acuminate at apex, cuneate or truncate at base, entire or faintly lobed, laterals oblique; flower 4-8, crowded at the end of short peduncles; bracts peltate; bracteoles linear; calyx 5-toothed, lower tooth deltoid-lanceolate, others linear-lanceolate, glabrous, teeth ciliate at margins; corolla yellow, much exserted, petals clawed, standard orbicular, wings narrow, keel curved appendaged; stamens diadelphous (9+1), anthers uniform, filaments slender; ovary pubescent, style incurved, apically bearded, stigma oblique; pod linear, cylindric, straight, minutely hairy; seeds 8-15, green or yellow.