Vines, woody. Stems slender, pubescent when young, then glabrous to almost glabrous. Leaves pinnately 3-foliolate; stipules small, narrowly triangular, ca. 2 mm, usually deciduous; petiole 2-4 cm, pubescent; petiolules 1-2 mm, pubescent; leaflets thinly papery; terminal leaflet larger, almost rhomboid or broadly ovate-rhomboid, 5-6 × 4-5.8 cm, abaxial surface sparsely pubescent and with dense yellowish brown sessile glands, adaxial surface almost glabrous, basal veins 3, base broadly rounded or subcuneate, apex acuminate; lateral leaflets obviously small, broadly obliquely ovate. Raceme axillary, 8-13 cm, pubescent, many flowered; pedicels 1-2 mm. Calyx ca. 8 mm, 5-lobed; lower lobe longest, subequal to tube. Corolla yellow, usually longer than calyx; standard transversely elliptic, 1-1.4 × 1.5-2 cm, base with 2 auricles; wings obovate-elliptic, base long clawed with auricle at one side; keels semiorbicular, long clawed. Legume linear-oblong, 5-7.5 × 0.8-1.2 cm, pubescent when young, later glabrous, apex with small beak, stipe ca. 2 cm. Seeds 6-10, dark brown, suborbicular, ca. 4 × 5 mm, with obvious strophiole. Fl. Sep-Oct, fr. Oct-Jan.