The _wood_ is heavy, hard, strong, tough and difficult to split. It is used for hubs of wheels, saddle trees, boats, ships, barrel hoops, and veneer for baskets and crates. Because of its spreading fan-shaped form, graceful pendulous branches, and long life, the white elm justly holds its place as one of the most desirable shade trees. The rock or cork elm, _Ulmus thomasi_ Sarg., is found occasionally in northern Illinois. Its excurrent branches are very different from those of other elms. Its twigs often have corky ridges and the winter buds are somewhat hairy. The winged elm, _Ulmus alata_ Michx., a small tree, is found in the southern part of the State. The twigs have two thin corky wings. +RED OR SLIPPERY ELM+ _Ulmus rubra_ Muhl. (_Ulmus fulva_ Michx.) THE red elm, or slippery elm, is a common tree in all sections of the State. It is found principally on the banks of streams and on low hillsides in rich soil. It is a tree of small to moderate size, but noticeably wide-spreading. It is usually less than 50 feet in height and 16 inches in diameter although trees of larger dimensions are occasionally found. [Illustration: SLIPPERY ELM Twig, one-half natural size. Leaf, one-half natural size.] The _bark_ on the trunk is frequently one inch thick, dark grayish-brown, and broken by shallow fissures into flat ridges. The inner bark is used to some extent for medical purposes, as it is fragrant and when chewed, affords a slippery, mucilaginous substance, whence the tree gets its name. The _winter buds_ are large and conspicuously rusty-hairy. The _leaves_ are simple, alternate on the stem, 4 to 6 inches in length, sharp pointed, their bases unsymmetrical, doubly-toothed on the edges, thick, dark green, and rough on both sides. The _fruit_ consists of a seed surrounded by a thin, broad, greenish wing, about one-half an inch in diameter; the _flowers_ appear in early spring and the fruit ripens when the leaves are about half-grown. The _wood_ is close-grained, tough, strong, heavy, hard, moderately durable in contact with the soil. It is used for fence posts, crossties, agricultural implements, ribs for small boats and for some other purposes. The water elm, _Planera aquatica_ Gmel., is a small tree with slender branches forming a low broad head and is found in swamps in the valley of the Wabash River in this State. It reaches its best development in Arkansas and Louisiana. It has dull green leaves 2 inches long and 1 inch wide. The fruit is an oblong, dark brown drupe. +HACKBERRY+ _Celtis occidentalis_ L.