Woody climbers. Branchlets dark brown or nearly blackish when dry, glabrous or sparsely puberulent. Leaves 4-6(-10) cm; rachis and petiole sparsely puberulent; stipules caducous, ovate; leaflets 31-41; petiolules short, subglabrous; blades narrowly linear-oblong, ca. 12 × 3 mm, both surfaces appressed sparsely puberulent when young, soon glabrous except abaxially on midvein, apex obtuse or rounded. Panicles axillary, 4-6 cm; peduncles, rachis, branches, and pedicels puberulent. Flowers small, 3-4 mm; bracteoles puberulent, basal persistent, lan-ceolate, epicalycine bracteoles embracing lower 1/3 of calyx tube, deciduous. Calyx campanulate, ca. 1.5 mm, sparsely puberulent; teeth short, upper pair obtuse, lateral acute, lowest longer than others, broadly lanceolate. Corolla white or pale yellow; petals shortly clawed; standard broadly ovate to suborbicular, emarginate; wings oblong; keel obovate, blade hastate on upper side below. Stamens 9, monadelphous; filaments alternately shorter and longer. Ovary long stipitate, sparsely pubescent along sutures, 3-ovuled; style short; stigma small. Legume ligulate to strap-shaped, 2.5-5 × ca. 0.75 cm, base attenuate to distinct stipe, apex subacute, 1-or 2-seeded. Seeds reniform, compressed. Fl. May-Jun, fr. Aug-Nov.