Herbs, perennial. Stems twining, slender, sparsely pubescent. Leaves pinnately 3-foliolate; stipules small, usually deciduous; petiole slender, 0.8-2.5 cm, pubescent; stipels extremely small; petiolules ca. 1 mm, densely pubescent; leaflets thinly papery; terminal leaflet larger, rhomboid or almost triangular, both surfaces sparsely pubescent, with reddish sessile glands, basal veins 3, lateral veins 1 or 2 pairs, base rounded, broadly cuneate, or almost truncate, apex acute or acuminate; lateral leaflets much smaller, oblique, 1.5-3.5 × 2-3.7 cm. Raceme or compound raceme axillary, 1.5-5 cm, densely pubescent, 2-7-flowered. Flower ca. 1.5 cm. Calyx campanulate, 5-9 mm, 4-lobed; lobes lanceolate or linear-lanceolate, unequal, usually lower one longest. Corolla yellow; standard almost orbicular or transversely elliptic, base auriculate on one side; keels similar to wings, but curved, shortly clawed, apex beaked. Ovary densely pubescent and with rubiginous glands. Legume linear-oblong, 3-5 × ca. 0.8 cm, compressed, pubescent or almost glabrous, apex beaked, stipe ± absent. Seeds 6 or 7, black, suborbicular, ca. 4 × 3 mm. Fl. Jul-Sep, fr. Aug-Oct.
Home