The _bark_ is rather thin and divided by shallow fissures into broad
ridges of a dark brown color.
The _leaves_ are alternate in arrangement along the stem, oblong in
shape, 4 to 6 inches long by 1 to 2 inches wide, leathery in texture
with smooth margins sometimes wavy in outline, dark green and shiny
above, and thick downy or velvety below.
The _fruit_ is an acorn about one-half inch in length, borne singly or
in pairs on stout stems, full or rounded at the end and faintly
streaked, enclosed for about one-half its length in a thin-walled cup.
Like all members of the black oak group, the fruit requires two seasons
to mature.
The _wood_ is heavy, hard, rather coarse-grained, and used for common
lumber, shingles (whence it gets its common name), posts and firewood.
The willow oak, _Quercus phellos_ L., is a river bottom tree rarely
found in southern Illinois. It is readily identified by its leaves,
which as the name implies, resemble those of the willows. These leaves
are from two to four inches long and one-half to one inch wide, light
green, shiny above and smooth beneath.
+AMERICAN ELM+ _Ulmus americana_ L.
THIS is a famous shade tree of New England, whose range, however,
extends to the Rocky Mountains and southward to Texas. Within this vast
area, it is generally common except in the high mountains. It reaches an
average height of 60 to 70 feet and a diameter of 4 to 5 feet. The
_bark_ is dark gray, divided into irregular, flat-topped thick ridges,
and is generally firm, though on old trees it tends to come off in
flakes. An incision into the inner bark will show alternate layers of
brown and white.
[Illustration: AMERICAN ELM