Annual or perennial herbs or shrubs. Flowers zygomorphic, papilionaceous, in terminal or lateral racemes, rarely solitary. Sepals unequal, 5, the 3 outer ones usually sepaloid (see note below) and the 2 inner ones (wings) larger and petaloid. The sepals are either all free or the 2 anterior ones are united. Petals 3(-5), the lowest one (the keel) usually crested; two lateral ones usually vestigial or 0, and 2 upper ones joined at the base to the keel. Stamens 8 (rarely 4 or 5), sometimes only 6 fertile with 2 staminodes. Ovary 2-locular. Fruit a flattened, capsule. Seeds 2, usually with a caruncle and with sericeous indumentum.
Of the three outer, sepaloid sepals, two are anterior and one posterior. It is helpful to examine these plants when fresh and to note whether the anterior sepals are free or united. If they are united, note also if there are 8 fertile stamens or 6 fertile and 2 staminodes.