Cal irregular, membranous, the 2 upper lobes connate most of their length, the lateral ones much shorter, the lowest one lanceolate, about equaling the upper; standard broadly obovate to suborbicular, much exceeding the other pet; wings short-clawed, the blade half-orbicular, minutely auriculate; keel boat-shaped, obtuse; stamens 10, monadelphous, the tube closed; anthers alternately oblong and globose; fr transversely segmented and eventually separating into 1-seeded indehiscent joints; herbs with palmately compound 2- or 4-foliolate lvs and mostly small fls in interrupted terminal spikes, each fl subtended by a pair of large bracts. 80, warm reg.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.