The _bark_ of the sycamore is a characteristic feature. On the younger
trunk and large limbs it is very smooth, greenish-gray in color. The
outer bark yearly flakes off in large patches and exposes the nearly
white younger bark. Near the base of the old trees the bark becomes
thick, dark brown and divided by deep furrows. The _flowers_ are very
small and arranged in dense globular green heads.
The _leaves_ are simple, alternate, 4 to 7 inches long and about as
broad, light green and smooth above, and paler below. The base of the
leafstalk is hollow and in falling off exposes the winter bud. The
_fruit_ is a ball about 1 inch in diameter, conspicuous throughout the
winter as it hangs on its flexible stem, which is 3 to 5 inches long.
During early spring, the fruit ball breaks up, and the small seeds are
widely scattered by the wind.
The _wood_ is hard and moderately strong, but decays rapidly in the
ground. It is used for butchers' blocks, tobacco boxes, furniture and
interior finish.
The tree grows rapidly, bears transplanting well and is often planted as
a shade tree.
The European sycamore or London plane tree, _Platanus acerifolia_
Willd., is less subject to disease than our native species and has
been widely planted in this country for ornament and shade. The leaves
are more deeply lobed than our sycamore and there are two or three
fruit balls on each stem.
+WILD CRAB APPLE+ _Malus ioensis_ Britton
THE wild crab apple, or prairie crab, is found throughout Illinois
forming small trees 20 to 30 feet high with trunks from 6 to 12 inches
in diameter. In the open it develops a broad open crown with rigid,
contorted branches bearing many short, spur-like branchlets, some of
which develop into sharp rigid thorns. Under less favorable conditions,
these crab apples often form bushy shrubs.
[Illustration: WILD CRAB APPLE