Large, robust, prickly climber with straggling branches, grey, downy, pubescent, prickles recurved; leaves stipulate, bipinnate, 15-22 cm long, pinnae 4-8 pairs, prickly; leaflets 7-9 pairs, large, ovate-elliptic, glabrous above, pubescent below, base truncate, rotund, margins entire, apex obtuse, mucronate; peduncles very short; pedicels as long as calyx tube; bracts ascending small; flowers pale yellow in terminal and supra-axillary racemes; calyx tube campanulate, gibbous at base, sepals 5, unequal, imbricate, oblong-obovate, tomentose; petals 8, oblong, upper one smaller, apex obtuse, marked with yellow streaks; stamen 10, free, declinate, anthers oblong, uniform, versatile; ovary sessile, few ovuled, style filiform, stigma minute; pods armed all over with sharp wiry spines, oblong, flattened or turgid, not winged along sutures; seeds ovate to orbicular.