Perennial twining vines. Stems weak, sparsely pubescent. Pinnate compound leaves with 3 leaflets; The petiole is 0.8-2.5 cm long; The terminal leaflets are rhombic and round, long 1.5-2.7 cm, slightly wider than long, with blunt or round top, round base, sparsely pubescent or subglabrous on both sides, with dark brown glandular spots, especially below; Lateral leaflets are slightly smaller, oblique, and the edges are microwave-like. Flowers 1-2 are born in leaf axils; Calyx bell-shaped, 2-5 mm long, calyx teeth 5, ovate-lanceolate, densely reddish-brown glandular punctate and pubescent; Corolla yellow, length 1- 1.5 cm, flag petal obovate, with 1 spike on both sides of petal base, wing petal obovate, slightly curved, keel petal sickle-shaped, with blunt beak at the top; Ovary sparsely pubescent, sessile. Pods are linear, rectangular, flat, slightly curved, 3-5 cm long, 8 mm wide, sparsely pubescent or subglabrous, with needle-like tips and no fruit stalks. Seeds 6-8, suborbicular, dark brown.