The aspen is a small tree, reaching heights of 40 to 60 feet and
diameters of 10 to 20 inches. The young branches are reddish-brown soon
turning gray. The _winter buds_ are about 1/4 inch long, pointed and
shining. The _bark_ is thin, smooth, light gray tinged with green.
The _leaves_ are on slender flat petioles, arranged alternately on the
twigs, and broadly oval, short pointed and shallowly toothed. They are
green, shiny above and dull below, ranging from 2 to 4 inches long and
about the same in breadth.
The _flowers_ are in catkins and appear before the leaves begin to
expand. The two kinds are borne on separate trees, the staminate catkins
are about 2 inches long, but the seed-producing flowers form a long
slender cluster 4 inches in length. The _fruit_ is a conical capsule
filled with tiny cottony seeds which ripen in late spring before the
leaves are fully expanded.
The _wood_ is light brown, almost white. It is light, weak and not
durable, and is used for pulpwood, fruit-crates and berry boxes.
The large-tooth aspen, _Populus grandidentata_ Michx., is found in the
northern half of Illinois and frequently grows alongside the quaking
aspen. Its leaves are larger than those of the quaking aspen and the
edges are coarsely and irregularly toothed. The winter buds have dull
chestnut-brown scales and are somewhat downy. The bark is light gray
tinged with reddish-brown.
+COTTONWOOD+ _Populus deltoides_ Marsh.
THE cottonwood, or Carolina poplar, is one of the largest trees in
Illinois, growing on flood plains along small streams and in depressions
in the prairie. It is one of the best trees for forestry purposes for
planting where quick shade is desired. The wood is soft, light, weak,
fine-grained but tough. It is good for pulp, boxes and berry baskets.
[Illustration: COTTONWOOD