Erect shrub or shrublet, 0.4-2 m. Leaves 3-foliolate, leaflets subterete, often oblong-ovoid, sausage-shaped, sometimes pungent. Flowers scattered along branch ends, bright yellow, fading black when dried, wings and keel glabrous, calyx glabrous or thinly hairy, lobes triangular to awl-shaped, sometimes pungent, glabrous.