Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Genus Description - Cal-tube broadly campanulate; cal-lobes triangular, equal or nearly so; standard narrowly obovate, tapering to the base; wings oblong to nearly linear, usually shorter than the keel, the blade auriculate at base; keel-pet obtuse, semirhombic-ovate; stamens diadelphous; ovary elongate; fr indehiscent, transversely segmented and ultimately separating into joints; perennial herbs with odd-pinnate lvs and elongate, peduncled, axillary racemes. 100, mostly boreal and N. Temp.