THE sycamore, also called buttonwood, is considered the largest hardwood tree in North America. It occurs throughout the State, but is most abundant and reaches its largest size along streams and on rich bottom lands. It is one of the more rapidly-growing trees. In maturity it occasionally attains a height of 140 to 170 feet and a diameter of 10 to 11 feet. It often forks into several large secondary trunks, and the massive spreading limbs form an open head sometimes 100 feet across. [Illustration: SYCAMORE Leaf, one-third natural size. Twig, one-half natural size.] The _bark_ of the sycamore is a characteristic feature. On the younger trunk and large limbs it is very smooth, greenish-gray in color. The outer bark yearly flakes off in large patches and exposes the nearly white younger bark. Near the base of the old trees the bark becomes thick, dark brown and divided by deep furrows. The _flowers_ are very small and arranged in dense globular green heads. The _leaves_ are simple, alternate, 4 to 7 inches long and about as broad, light green and smooth above, and paler below. The base of the leafstalk is hollow and in falling off exposes the winter bud. The _fruit_ is a ball about 1 inch in diameter, conspicuous throughout the winter as it hangs on its flexible stem, which is 3 to 5 inches long. During early spring, the fruit ball breaks up, and the small seeds are widely scattered by the wind. The _wood_ is hard and moderately strong, but decays rapidly in the ground. It is used for butchers' blocks, tobacco boxes, furniture and interior finish. The tree grows rapidly, bears transplanting well and is often planted as a shade tree. The European sycamore or London plane tree, _Platanus acerifolia_ Willd., is less subject to disease than our native species and has been widely planted in this country for ornament and shade. The leaves are more deeply lobed than our sycamore and there are two or three fruit balls on each stem. +WILD CRAB APPLE+ _Malus ioensis_ Britton THE wild crab apple, or prairie crab, is found throughout Illinois forming small trees 20 to 30 feet high with trunks from 6 to 12 inches in diameter. In the open it develops a broad open crown with rigid, contorted branches bearing many short, spur-like branchlets, some of which develop into sharp rigid thorns. Under less favorable conditions, these crab apples often form bushy shrubs. [Illustration: WILD CRAB APPLE Flower, fruit and leaves one-half natural size.] The _bark_ on the branches is smooth, thin and red-brown in color, while on the trunk the thicker bark often breaks into scales. The twigs are at first hoary-hairy, but soon become smooth and reddish. The _leaves_ are alternate, simple, 3 to 4 inches long and almost as broad. They are sometimes slightly lobed and sharply and deeply toothed. They are dark green and shiny above, but pale and hairy beneath, borne on stout, hairy petioles.