Forest Trees of Illinois Part 10

Twig, one-half natural size.]

The _leaves_ are 3 to 5 inches across, simple, opposite, with 3 to 5 pointed and spa.r.s.ely-toothed lobes, the divisions between the lobes being rounded. The leaves are dark green on the upper surface, lighter green beneath, turning in autumn to brilliant shades of dark red, scarlet, orange and clear yellow.

The _flowers_ are yellowish-green, on long threadlike stalks, appearing with the leaves, the two kinds in separate cl.u.s.ters. The _fruit_, which ripens in the fall, consists of a two-winged "samara", or "key", the two wings nearly parallel, each about 1 inch in length and containing a seed. It is easily carried by the wind.

The _wood_ is hard, heavy, strong, close-grained and light brown in color. It is known, commercially as hard maple, and is used in the manufacture of flooring, furniture, shoe-lasts and a great variety of novelties.

The black maple, _Acer nigrum_ Michx., occurs with the sugar maple with darker bark. The leaves are usually wider than long, yellow-green and downy beneath, and the base of the petioles enlarged. The two lower lobes are very small; the lobes are undulate or entire.

+SILVER MAPLE+ _Acer saccharinum_ L.

THE silver or river maple, also called the soft maple, occurs on moist land and along streams. It attains heights of 100 feet or more and diameters of 3 feet or over. It usually has a short trunk which divides into a number of large ascending limbs. These again subdivide, and the branches droop but turn upward at the tips. The _bark_ on the old stems is dark gray and broken into long flakes or scales; on the young shoots it is smooth and varies in color from reddish to a yellowish-gray. The silver maple grows rapidly and has been much planted as a shade tree.

Because of the brittleness of its wood, it is often damaged by summer storms and winter sleet.

[Ill.u.s.tration: SILVER MAPLE

Twig, one-half natural size. Leaf, one-third natural size.]

The _leaves_ are opposite on the stem, have from 3 to 5 lobes ending in long points with toothed edges and are separated by deep angular sinuses or openings; they are pale green on the upper surface and silvery-white underneath. The buds are rounded, red or reddish-brown, blunt-pointed; generally like those of red maple.

The _flowers_ appear in the spring before the leaves, in dense cl.u.s.ters, and are of a greenish-yellow color. The _fruit_ ripens in late spring.

It consists of a pair of winged seeds or "keys" with wings 1 to 2 inches long on slender, flexible, threadlike stems about an inch long.

The _wood_ is soft, weak, even-textured, rather brittle, easily worked, and decays readily when exposed. It is considerably used for boxboards, furniture, veneers and fuel.

The red maple, or swamp maple, _Acer rubrum_ L., has leaves deeply lobed with the lobes sharply toothed. The autumn color is deep red.

The flowers also are red and the fruit is small reddish, maturing late in spring.

+BOX ELDER+ _Acer negundo_ L.

THE box elder is a fairly rapidly growing tree, found commonly along streams rather generally over the State. It is a tree of medium size, rarely reaching over 24 inches in diameter and 60 to 70 feet in height.

It has been considerably planted for shade because in good soil its growth is rapid. Its limbs and branches, however, are fragile, and the tree as a whole is rather subject to disease. It is not long-lived or generally satisfactory for any purpose. It is prolific in reproduction but is largely destroyed by grazing and cultivation.

[Ill.u.s.tration: BOX ELDER

Twig, two-thirds natural size. Leaf, one-third natural size.]

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 l.u.s.trous, 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 coa.r.s.e 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.

[Ill.u.s.tration: OHIO BUCKEYE

Twig, two-thirds natural size. Nut, one-third natural size.

Leaf, one-quarter natural size.]

The _leaves_ are opposite on the twigs, compound and consisting of 5 long-oval, rarely 7, pointed, toothed, yellow-green leaflets, set like the fingers of a hand at the top of slender petioles 4 to 6 inches long.

They usually turn yellow and then fall early in the autumn.

The _flowers_ appear after the leaves unfold; are cream-colored; in terminal panicles 5 to 7 inches long and 2 to 3 inches broad, quite downy.

The _fruit_ is a thick, leathery, p.r.i.c.kly capsule about an inch in diameter, and, breaking into 2 or 3 valves, discloses the bright, s.h.i.+ny, mahogany colored seeds, or nuts.

The _wood_ is light, soft and weak, and decays rapidly when exposed. It is used for woodenware, artificial limbs, paper pulp, and for lumber and fuel.

The horse-chestnut, _Aesculus hippocastanum_ L., is a handsome European tree with a very symmetrical crown. The flowers are larger than those of our native species and add beauty to the foliage. It forms a desirable shade tree.

+Ba.s.sWOOD+ _Tilia americana_ L.

THE ba.s.swood, or American linden, is a rather tall tree with a broad, round-topped crown. It ranges throughout Illinois and may be found wherever rich, wooded slopes, moist stream banks and cool ravines occur.

It grows best in river bottoms, where it is common and forms a valuable timber tree, attaining a height of 80 feet and a diameter of 4 feet. The _bark_ is light brown, deeply furrowed and the inner bark furnishes bast for making mats.

[Ill.u.s.tration: Ba.s.sWOOD

Leaf, one-third natural size. Twig, one-half natural size.]

The _leaves_ are broadly heart-shaped, 3 to 6 inches long, coa.r.s.ely saw-toothed, smooth on both sides, except for some hairs on the axils of the veins. They are dark above but light green beneath.

The _flowers_ are yellowish-white, in drooping cl.u.s.ters opening in early summer, and flower stem is united to the middle of a long narrow leaf-like bract. They are very fragrant and from them the bees make a large amount of choice grade honey.

The _fruit_ is a berry-like, dry, 1 or 2 seeded, rounded nutlet 1/4 to 1/2 an inch in diameter, covered with short, thick and brownish wool. It remains attached in cl.u.s.ters to the leafy bract, which later acts as a wing to bear it away on the wind.

The _wood_ is light, soft, tough, not durable, light brown in color. It is used in the manufacture of pulp, woodenware, furniture, trunks, excelsior and many other articles.

It makes a fine shade tree, grows rapidly and is easily transplanted.

The white ba.s.swood, _Tilia heterophylla_ Vent., is similar to the preceding species, but with somewhat lighter bark. The leaves are larger, dark yellow-green above, the under surface being generally densely covered with short, silvery or gray hairs with tufts of brown hairs in the axils of the veins. It is more plentiful in the southern part of the State.

+FLOWERING DOGWOOD+ _Cornus florida_ L.