A large family, most of them tropical; trees, shrubs, and herbs, with flowers more or less irregular in form, but not like the flowers of the true Pea, though sometimes resembling them; calyx usually with five sepals; corolla with five petals, overlapping in the bud, the petal which corresponds to the standard folded within the two side petals, instead of covering them, as in the Pea flower; stamens, ten, or fewer, in number, usually not united; ovar superior; fruit a pod, mostly splitting into two halves, containing one to many seeds. To this family belong the handsome Red-bud, or Judas Tree, of our woodlands, both East and West; the spiny Honey-locust; the Kentucky Coffee-tree, with its fine foliage, of the central and eastern states; the interesting Palo Verde, with greatly reduced leaves, of the Southwest, and the fine Bird-of-paradise flowers, of the tropics and Mexico, one or two of which are just beginning to grow wild in southern Arizona and California.

There are many kinds of Cassia, abundant in tropical America; herbs, shrubs, or trees; leaflets even in number; flowers usually yellow; calyx-teeth nearly equal; corolla almost regular, with five, nearly equal, spreading petals, with claws; stamens usually ten, sometimes five, often unequal, some of the anthers often imperfect, or lacking; pod flat or cylindrical, often curved, sometimes with partitions between the numerous seeds.