Slender bush clover is an erect forb with purple flowers, 6-8mm, and cleistogamous flowers lacking petals, chiefly along the middle of the stem in small, subsessile clusters, chasmogamous flowers are showy, in short, few-flowered racemes from the upper axils. Peduncles are shorter than the leaves, forming a crowded, leafy inflorescence. Calyx lobes of the chasmogamous flowers are 1.7-3mm, the 2 uppermost fused together to the middle or beyond. Fruits are thinly and inconspicuously covered with straight, stiff hairs. Leaves are usually erect or strongly ascending, composed of 3 leaflets that are linear to narrowly oblong, 3-7mm wide and 4-6 times as long.