Slender to stout scrambling or tufted annual; stem sparsely hairy. Lvs sparsely to densely hairy; tendrils branched; leaflets in (3)-4-8 pairs, often alternate, linear to elliptic to obovate, (5)-10-30-(40) mm long; stipules simple or with 1, adaxial, basal lobe, or dentate, usually with a dark spot. Infl. much < lvs, 1-2-(4)-flowered. Peduncle much < fls, rarely ± = fls. Pedicel 1-5 mm long. Calyx somewhat gibbous at base; calyx teeth ± equal, <, =, or > tube. Corolla usually purple, reddish purple or rose, sometimes white or pink, (8)-12-28 mm long; limb of standard > claw. Pod ± glabrous or puberulent, blackish or brownish black, constricted or not between seeds, 5-12-seeded, (20)-30-60 mm long; seeds light or dark brown with dark spots; hilum ⅙-⅕ of circumference.