(ancient Latin name). Betulaceae. Hornbeam. Trees cultivated for their handsome foliage, assuming bright autumnal tints; also for the light green attractive fruit-clusters.

Deciduous trees or rarely shrubs: winter-buds conspicuous, acute with many imbricate scales: leaves alternate, petioled, serrate, with deciduous stipules: flowers monoecious; staminate catkins pendulous, each scale bearing 3-13 stamens, 2-forked at the apex; pistillate catkins terminal, slender, each scale bearing 2 ovaries, the bracts and bractlets of which develop into a large, leafy, more or less 3-lobed bract, embracing the small, nut-like fruit at their base. - About 20 species, most of them in Cent. and E. Asia, 5 in Eu. and W. Asia and 1 in N. and Cent. Amer. Monogr. by Winkler in Engler, Pflanzenreich, Betulaceae, hft. 19, pp. 24-43, quoted below as W. B.

The hornbeams are trees usually with dense round head, rarely shrubby, with medium-sized, bright green ovate to lanceolate leaves and rather insignificant flowers appearing with the leaves and followed by pendulous catkins consisting of large bracts bearing a small nutlet in their axils. The wood is very hard and close-grained, and much used in making tools and other small articles. The handsome foliage is rarely attacked by insects, and assumes a yellow or scarlet color in fall. The most beautiful are C. cordata, with large leaves, and C. japonica, of graceful habit and with elegant foliage. The European hornbeam bears severe pruning well, and is very valuable for high hedges; it was formerly much used in the old formal gardens for this purpose; it makes, also, an excellent game cover, as it retains its withered foliage almost throughout the winter.

The species are of comparatively slow growth and thrive in almost any soil, and even in dry, rocky situations; most of them are quite hardy North. Propagated by seeds, sown usually in fall, germinating very irregularly; if they do not appear the first spring, the seedbed should be covered until the following spring with moss or leaf-mold, to keep the soil moist. If intended for hedges, the seedlings should be transplanted after the first year, and allowed sufficient space to prevent them from growing into slender tall plants, unfit for hedges. The varieties of rarer species are grafted in spring under glass, or in the open air on seedlings of one of the common species.

a. Leaves with 7-15 secondary veins: mature catkins with spreading narrow bracts.

Caroliniana

Walt. (C. americana, Michx. C. virgini-ana, Michx, f.). American Hornbeam. Blue Beech. Fig. 820. Bushy tree, rarely 40 ft.: leaves ovate-oblong, usually rounded at the base, acuminate, sharply and doubly serrate, glabrous at length, except in the axils of the veins beneath, 2-4 in. long: fruit - clusters peduncled, 2-4 in. long: bracts ovate or ovate-lanceolate, 3/4-l in. long, with 2 broad and short unequal lateral lobes, and a much longer middle lobe, usually serrate only on one margin. E. N. Amer., west to Minn, and Texas; also, in Mex. and Cent. Amer. S.S. 9:447. Em. 1:199. Gn. 24, p. 418. - Bushy tree, with dense, but slender and often somewhat pendulous branches, and dark bluish green foliage, changing to scarlet or orange-yellow in fall.

Carpinus caroliniana. (X 5/8)

Fig. 820. Carpinus caroliniana. (X 5/8)

Betulus, Linn. European Hornbeam. Tree, to 60 or 70 ft.: leaves similar to those of the former, cordate or rounded at the base, ovate or oblong-ovate, of somewhat thicker texture, and the veins more impressed above: fruit - clusters 3-5 in. long: bracts over 1 1/2 in. long, with ovate, lateral lobes, and much longer oblong-lanceolate middle lobe, the margins almost entire or remotely denticulate. Eu. to Persia. H.W. 2:17, pp. 31-33. W.B. 29. F.S.R. 3, p. 153. Gn. 24, pp. 418, 419, 420. - The most remarkable of the garden forms are the following: variety incisa, Ait. (variety asplenifolia, Hort.). Leaves incised or lobed, smaller. Gn. 24, p. 419. variety pyramidalis, Dipp. (variety fastigidta, Hort.). Of upright growth. variety purpurea, Dipp. Leaves purplish when young, green at length. - It grows into a taller tree than the American species, although the former is of more vigorous growth when young; the foliage turns yellow in fall, and remains on the tree throughout the winter.

aa. Leaves with 15-25 pairs of veins: mature catkins with loosely oppressed ovate and dentate bracts, of cone-like appearance. japonica, Blume (C. Carpinus, Sarg. Distego-carpus Carpinus, Sieb. & Zucc). Tree, to 50 ft.: young branchlets pubescent: leaves reddish brown when unfolding, oblong-ovate or oblong-lanceolate, 2-4 in. long, acuminate, rounded or subcordate at the base, unequally serrate, with 20-24 pairs of veins deeply impressed above, bright green and glabrous above, beneath brownish pubescent on the veins at first, finally glabrous or nearly so: mature catkins ovoid-oblong, 2 in. long, slender-peduncled; bracts inflexed at the base inclosing the nutlet. Japan. G.F. 6:365. R.H. 1895, p. 427. S.I.F. 1:24. - A very graceful species and quite hardy; sometimes cultivated under the name C. laxiflora, which is an entirely different species with the leaves having only 10-14 pairs of veins.

Cordata

Blume. Tree, to 40 ft.: young branchlets hairy at first, soon glabrous: leaves ovate or oblong-ovate, acuminate, distinctly cordate at the base, 3-6 in. long, unequally serrate, with 15-20 pairs of veins deeply impressed above, pubescent on the veins beneath or glabrous: mature catkins 2-3 in. long, slender-ped uncled; bracts not inflexed at .the base, but with an opposite bractlet about as long as the nutlet. Japan, Manchuria, Korea. G.F. 8:295. S.I.F. 1:24-A very handsome species and quite hardy.

C. americana, Michx.=C. caroliniana. - C. duinensis, Scop.= C. orientalis. - C. laxiflora, Blume. To 50 ft.: leaves ovate or elliptic-ovate, long-acuminate, 2-3 in. long, with 10-14 pairs of veins. Japan. S.I.F. 1:25. - Very attractive in fall, with its long and slender catkins. variety macrostachya, Winkl. Leaves ovate-oblong: fruiting catkins 2 1/2-3 1/2 in. long. W. China. H.I. 20:1989. - Recently introduced - C. orientalis. Mill. Bushy tree, to 15 ft.: leaves ovate or oblong-ovate, 1 1/2- 2 in. long, with about 10 pairs of veins. S.E. Eu. to Persia. Gn. 24, p. 418. - C. Paxii, Winkl.=C. Turczaninowii. - C. polyneura, Franch. (C. Turczaninowii variety polyneura, Winkl.). Small tree: young branchlets pubescent, soon glabrous: leaves ovate-lanceolate, long-acuminate, usually rounded at the base, 1 1/2 -2 1/2 in. long, with 15-20 pairs of veins; fruiting bractlets ovate to lanceolate, serrate. W. China. W.B. 39. - C. Turczaninowii, Hance (C. Paxii, Winkl.) Shrubby tree: leaves ovate, acute, 1-2 in. long, with 10-12 pairs of veins. N. China. - C. virginiana, Michx. f.=C. caroliniana. - C. yedoensis, Maxim. Small tree: branchlets and leaves beneath pubescent: leaves ovate-elliptic or ovate-lanceolate, with about 12 pairs of veins, 2-3 in. long.

Japan. S.I.F. 2:11. Alfred Rehder.