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.
[Illustration: Scotch Broom--Cytisus scoparius.]
[Sidenote: =Desert Senna, Golden Cassia=
_Cássia armàta_
=Yellow
Spring
Southwest=]
The peculiar orange-yellow of these handsome flowers at once
attracts our attention, for their tint is quite different from the
greenish-yellow, which is so much more common. They grow in the desert,
forming big clumps, two feet high and two or three feet across, but
have almost no foliage. The numerous, smooth stems are very pale
in color, often bluish or gray, with a few dark-green leaves, with
six, very small, stiff leaflets, and bearing clusters of numerous,
sweet-smelling flowers, almost regular and about three-quarters of an
inch across, with a downy calyx and the small, flat pod also downy.