I. The common name of a genus of trees (carpinus) having wood of a horny texture, and the general appearance of the beech, the leaves resembling those of the beech or birch. The hornbeams are included with the oaks in the order cupuliferoe. In the United States the genus is represented by C. Americana (Mx.), the American hornbeam, a small tree from 10 to 20 ft. high, growing along streams. Its leaves are ovate-oblong, doubly serrate, nearly smooth; the barren flowers are borne in catkins on the sides of the branches, and appear before the leaves expand; the fertile flowers come out of the same bud with the leaves. The mature catkins consists of a series of unequally three-lobed bracts, each subtending a small ovate, several-nerved nut. The American hornbeam, where it has had ample space in which to grow, is a low tree with a broad, round, crowded, leafy head, the lower branches bending nearly to the ground on every side. It is readily distinguished from other trees by its ridged trunk, which is clothed with smooth bark of a slaty or bluish color, on which account it is often called, especially in western localities, the blue beech; the ridges, which run down from the under sides of the branches, are often so strong as to give the trunk the appearance of a fluted column.
It is thus a tree of some claim to beauty, and it forms an interesting object in the forest, especially in autumn, at which season there are few trees which present a greater variety of brilliant tints. Easily cultivated, it is worthy of regard in arboriculture. The close-grained, white wood is used for levers, beetles, and other purposes where great strength is required, and is frequently called ironwood. Its geographical range is from Canada to the gulf of Mexico. The common hornbeam of Europe (C. betulus, Linn.) is a small rigid tree, which under favorable circumstances will reach to the height of 60 or 70 ft.; but it is very seldom allowed to become a timber tree; as it grows freely after being cut down, it is generally grown in copses to furnish small wood; this was formerly used as a hedge plant and in forming bosquets. The tree seems to have been well known to the ancients, and was called by the Greeks or yoke tree from the use made of its wood. The oriental hornbeam (C. orientalis, Lamarck) is only a dwarf tree or shrub, rising to the height of 12 ft., and found wild in Asia Minor and the Levant. Its leaves are much smaller, and the branches grow closer together, than those of the English hornbeam. There are a few other little known and unimportant species. II. Hop Hornbeam, a tree of the genus ostrya (the ancient classical name), closely related to carpinus in botanical characters; in this the bracts of the fertile aments are tubular, and at maturity each becomes a closed, bladdery, oblong bag, enclosing a smooth nut; these bag-like involucres together form a sort of strobile, in size and appearance so like that of the hop as to justify the common name. The tree, which has the same geographical range as the American hornbeam, never attains a large size, and bears a strong general resemblance to the black birch in manner of growth and the shape of its leaves; it is a handsome tree when in fruit, and is worthy of the attention of those planting for ornament. The wood has the same general character as that of the hornbeam, is used for the same purposes, and like that is called ironwood.
The European hop hornbeam (0. vulgaris), a native of southern Europe, so closely resembles our native tree that some have supposed that they may bo forms of the same species.
European Hornbeam (Carpinus betulus).
Hop Hornbeam (Ostrya Virginica).