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.
