Scrambling or ± erect perennial herb; stem ribbed, almost glabrous to densely clothed in appressed hairs. Lvs almost glabrous or moderately clothed in appressed hairs below; stipules triangular, acuminate, sometimes with a basal lobe; leaflets subsessile, elliptic to obovate, obtuse, usually shortly mucronate, in 3-5 ± opposite pairs, 15-35-(45) mm long. Infl. racemose, = or > lvs, many-flowered; bracts subtending pedicels ovate to lanceolate, 3-8 mm long; pedicels c. 2 mm long. Calyx sparsely to moderately hairy; calyx teeth = or > tube, narrowly triangular, acuminate. Corolla crimson, 12-18 mm long. Pod 5-15 mm long, with 1-4, glabrous, densely spinous segments; seeds smooth, brown.