Herbs, shrubs, climbers or trees. Leaves usually alternate, simple or compound (3-foliolate or pinnate, sometimes with pinnae modified into tendrils); stipules often present. Flowers in spikes racemes or heads, bisexual, irregular. Sepals usually 5, usually basally connate into a tube. Petals 5, imbricate, the posterior one (standard) larger and outside the 2 lateral ones (wings); the two anterior petals connate or coherent along the lower margins forming the keel which envelopes the stamens and carpel. Stamens perigynous, usually 10; either all free, or the filaments all connate into a tube which is sometimes open on the upper side, or the upper stamen free. Ovary superior, 1-carpellate, 1-locular; placentas marginal; ovules 1–many; style simple. Fruit a legume, achene or lomentum. 500 gen., cosmop.