The _leaf_ is pinnate, or feather-like with 18 to 28 leaflets; or it is
twice-pinnate, consisting of 4 to 7 pairs of pinnae or secondary
leaflets, each 6 to 8 inches long and somewhat resembling the leaf of
the black locust.
The _flowers_ which appear when the leaves are nearly full-grown are
inconspicuous, greenish-yellow and rich in honey. The petals vary from 3
to 5, the stamens are 3 to 10 and the ovary is wooly and one-celled.
The _fruit_ is a pod, 10 to 18 inches long, often twisted, 1 to 1-1/2
inches wide, flat, dark brown or black when ripe and containing yellow
sweetish pulp and seeds. The seeds are very hard and each is separated
from the others by the pulp. The pods are eaten by many animals, and as
the seeds are hard to digest, many are thus widely scattered from the
parent tree.
The _wood_ is coarse-grained, hard, strong and moderately durable in
contact with the ground. It is used for fence posts and crossties. It
should not be confused with the very durable wood of the black locust.
The water locust, _Gleditsia aquatica_ Marsh., is found in river
bottoms in southern Illinois, becoming a medium sized tree. It may be
known by its short pods, 1 to 2 inches long, with only 2 or 3 seeds.
+REDBUD+ _Cercis canadensis_ L.
THE redbud is a small tree occurring under taller trees or on the
borders of fields or hillsides and in valleys throughout the State. It
ordinarily attains a height of 25 to 50 feet and a diameter of 6 to 12
inches. Its stout branches usually form a wide flat head.
[Illustration: REDBUD
Leaf, one-fourth natural size. Twig, and flowers, two-thirds natural
size.]
The _bark_ is bright red-brown, the long narrow plates separating into
thin scales.
The _leaves_ are alternate, heart-shaped, entire 3 to 5 inches long and
wide, glossy green turning in autumn to a bright clear yellow.
The conspicuous bright purplish-red, pea-shaped _flowers_ are in
clusters along the twigs and small branches and appear before or with
the leaves in early spring.
The _fruit_ is an oblong, flattened, many seeded pod, 2 to 4 inches
long, reddish during the summer, and often hanging on the tree most of
the winter.
The _wood_ is heavy, hard, not strong, rich, dark brown in color, and of
little commercial importance. The redbud is cultivated as an ornamental
tree and for that purpose might be planted more generally in this State.
The Kentucky coffee-tree, _Gymnocladus dioicus_ K. Koch, though not
anywhere a common tree, is found on rich bottom lands throughout the
State. The much-divided leaves are 2 to 3 feet long. The pods are 5 to
8 inches long and 1 to 2 inches wide and contain hard seeds 3/4 inch
long. It has few qualities to recommend it for ornamental planting.
+BLACK LOCUST+ _Robinia pseudoacacia_ L.
THE black locust is a native to the Appalachian Mountains but has been
introduced into Illinois, and now occurs throughout the entire State
growing on all soils and under all conditions of moisture except in
swamps. It is found generally in thickets on clay banks and waste places
or along fence rows.
[Illustration: BLACK LOCUST