The bark on young branches is smooth and green to purple in color; on old trees it is thin, grayish to light brown and deeply divided.
The leaves are compound, with usually 3 leaflets (rarely 5 or 7), opposite, smooth and lustrous, green, and borne on a leaf stem or petiole 2 to 3 inches long. The leaflets are 2 to 4 inches long by 1 to 2 inches wide, making the whole leaf 5 to 8 inches in length.
The fruit is a samara, or key, winged similarly to that of a sugar maple, but smaller. It ripens in late summer or early fall, and so is like its close relative, the sugar maple, but unlike its close relatives, the red maple and silver maple.
The wood is soft, light, weak, close-grained and decays readily in contact with heat and moisture. It is used occasionally for fuel.
The Norway maple, Acer platanoides L., is a European species which has been extensively planted. It forms a round, spreading crown of stout branches with coarse twigs. The leaves resemble those of the sugar maple but somewhat broader and the petioles exude a milky juice when cut. The flowers are larger than those of our native maples and fruit is large with diverging wings. It holds its leaves longer in the fall and the autumn coloring is pale yellow. It succeeds well as a city shade tree.
OHIO BUCKEYE Aesculus glabra Willd.
THE buckeye is rare in the northern fourth of Illinois, but is known in the rest of the State, forming no considerable part of the forest stand. It reaches a height of 60 to 70 feet and a diameter of 18 to 24 inches. The trunk is usually short, limby, and knotty. The crown or head, is generally open and made up of small spreading branches and twigs orange-brown to reddish-brown in color. The bark is light gray and, on old trees, divided or broken into flat scales, which make the stem of the tree rough; the bark is ill-smelling when bruised.