Twig, one-half natural size. Leaf and fruit, one-fourth natural size.]

The compound _leaves_ are 6 to 18 inches long, composed of 9 to 27

leaflets with sharply notched margins. They are dark green above,

whitish beneath, changing to red, purple and yellow early in the autumn.

The _flowers_ are small and green, produced in dense terminal panicles.

The _fruit_ is a small globose berry, covered with crimson hairs and has

a pleasant acid taste. The conspicuous deep red panicles of fruit remain

unchanged on the tree during the winter.

The _wood_ is light and of a golden yellow color. Either as a tree, or

as a shrub, the smooth sumac is excellent for ornamental planting, being

particularly desirable on terraces or hillsides, where mass effects are

desired. It transplants very readily and spreads freely.

The staghorn sumac, _Rhus typhina_ L., is a slightly taller tree, as

it reaches a height of 20 to 35 feet, and a stem diameter of 8 to 12

inches. The twigs and leaves are similar to those of the smooth sumac

but are conspicuously hairy. Its occurrence is limited to the northern

part of the State.

The shining sumac, _Rhus copallina_ L., usually occurs in shrub form

but it occasionally reaches a height of 20 feet with a stem diameter

of 6 inches. The leaves are smooth above but somewhat hairy beneath

with a winged rachis and about 9 to 21 leaflets that are slightly

toothed. Late in the summer its foliage turns a brilliant red. The

fruit clusters are much smaller than the preceding species. It is

found throughout the State.

+SUGAR MAPLE+ _Acer saccharum_ Marsh.

THE sugar maple is an important member of the climax forests which

stretch from Maine to Minnesota and southward to Texas and Florida. It

is an associate of the hemlocks and the birches in the North, with the

beeches and chestnuts through the middle states, with the oaks in the

West and with the tulip and the magnolias in the South. In Illinois it

is a common and favorite tree throughout the State. In the open it grows

fairly rapidly and has a very symmetrical, dense crown, affording heavy

shade. It is, therefore, quite extensively planted as a shade tree. The

_bark_ on young trees is light gray and brown and rather smooth, but as

the tree grows older, it breaks up into long, irregular plates or

scales, which vary from light gray to almost black. The twigs are smooth

and reddish-brown, and the _winter buds_ are smooth and sharp-pointed.

The tree attains a height of more than 100 feet and a diameter of 3 feet

or more. The sap yields maple sugar and maple syrup.

[Illustration: SUGAR MAPLE

Leaf, one-third natural size.

Forest Trees of Illinois: How to Know Them · 第 100 / 124 题