A twining herbaceous plant. Leaves are trifoliate, composed of three linear or oval-shaped leaflets. Upper leaves are often very long and narrow, whereas lower leaves are more usually oval-shaped. Leaflet surfaces hairless or sparsely hairy. Flowers are typical ëpeaí flowers of mauve and purple or pale blue. Flowers are followed by long, straight or slightly curved pods. Up to 12 roughly cube-shaped seeds are held in each pod. These are dark and firm at maturity.