Woody climbers. Branches sometimes hooked, blackish when dry, glabrous. Leaves 4-5 cm; stipules caducous, narrowly lanceolate, 2-3 mm; petiole and petiolules glabrous; leaflets 23-35, small, closely set, linear or narrowly oblong, (4-)10-15 × (2-)3-5 mm, both surfaces glabrous, base rounded or obtuse, somewhat unequal on two sides, apex truncate, sometimes emarginate; distal ones often obovate or obovate-oblong. Panicles axillary, compact, 1-1.5 cm; peduncles, rachis, and branches very sparsely puberulent. Pedicel very short. Flowers minute, 2.5-3 mm; bracts persistent; bracteoles deciduous, ovate, ciliate, embracing lower 1/3 of calyx tube. Calyx campanulate, ca. 1 mm, nearly glabrous; teeth short, subequal in length, lateral ovate, upper 2 rounded, subconnate, obtuse except for lowest, lowest triangular, acute. Corolla white; petals shortly clawed; standard orbicular, emarginate; wings ovate-oblong; keel oblong. Stamens 9, monadelphous. Ovary stipitate, sparsely pilose, 2-or 3-ovuled; style short; stigma small. Legume stipitate, oblong to linear, compressed, 4-6 × 1.2-1.6 cm, glabrous, leathery, reticulate veined throughout, but more conspicuously so opposite 1 seed, rarely 2-seeded, base broadly cuneate, apex obtuse or rounded. Seeds reniform, compressed, 8-12 × ca. 6 mm. Fl. May, fr. Aug.