Fls resupinate, the banner lowermost; cal somewhat gibbous at base, irregular, the 2 upper lobes partly connate, shorter than the lower; standard rotund-obovate, retuse, narrowed to the base, much exceeding the other pet; keel-pet strongly incurved but not twisted, shorter than the wings and coherent with them to the middle; stamens 10, monadelphous below; anthers all alike; style strongly incurved, pubescent on the concave side; fr stipitate, linear-oblong, flattened, dehiscent, several-seeded; twining herbs or shrubs with pinnately 3-9-foliolate, stipellate lvs and large, bracteolate fls solitary or in small clusters on axillary peduncles. 40, warm reg.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.