Trees, to 15 m tall. Branches glabrous. Leaves 10-20 cm, glabrous; stipules caducous; petiolules ca. 5 mm; leaflets 4 or 5 pairs, ovate, narrowly ovate, or elliptic-lanceolate, 6-12 × 3.5-6 cm, glabrous, asymmetric, upper side narrower than lower side, base rounded or broadly cuneate, margin entire, apex acuminate or shortly acuminate. Panicles in axils of apical leaves, 15-20(-30) cm, together with bracteoles, calyx, petal, and ovary densely yellowish pubescent; bracts triangular, 5-10 mm. Pedicels 2-4 mm, with 1 or 2 bracteoles from middle upward; bracteoles elliptic-lanceolate, ca. 5 mm. Calyx lobes 4, outside with bristles, inside densely yellowish hirsute. Petal thick, ca. 8 mm. Filaments filiform, 1-1.5 cm, densely yellowish pubescent at base; anthers 3-4 mm. Ovary shortly stalked, without prickles; style convolute, 1-1.5 cm, glabrous. Legume suborbicular or elliptic, 7-10 × 4-6 cm, apex beaked, smooth, without prickles. Seeds 2-5, blackish, spheroidal. Fl. May-Jun, fr. Aug-Sep.