CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT GENERA.
Scales of the pistillate ament deciduous; nut wingless, more or less inclosed in an involucre formed by the enlargement of the bract and bractlets of the flower; staminate flowers solitary in the axils of the scales of the ament; calyx 0; pistillate flowers with a calyx. Staminate aments covered during the winter: involucre of the fruit flat, 3-cleft, foliaceous.1. [Carpinus.] Staminate aments naked during the winter: involucre of the fruit bladder-like, closed.2. [Ostrya.] Scales of the pistillate ament persistent and forming a woody strobile; nut without an involucre, more or less broadly winged; staminate flowers 3—6 together in the axils of the scales of the ament; calyx present; pistillate flowers without a calyx. Pistillate aments solitary, their scales 3-lobed, becoming thin, brown, and woody, deciduous; stamens 2; filaments 2-branched, each division bearing a half-anther; winter-buds covered by imbricated scales.3. [Betula.] Pistillate aments racemose, their scales erose or 5-toothed, becoming thick, woody, and dark-colored, persistent; stamens 1—3 or 4; filaments simple; wings of the nut often reduced to a narrow border; winter-buds without scales.4. [Alnus.]
1. CARPINUS L. Hornbeam.
Trees, with smooth close bark, hard strong close-grained wood, elongated conic buds covered by numerous imbricated scales, the inner lengthening after the opening of the buds. Leaves open and concave in the bud, ovate, acute, often cordate; stipules strap-shaped to oblong-obovate. Flowers: staminate in aments emerging in very early spring from buds produced the previous season near the ends of short lateral branchlets of the year and inclosed during the winter, composed of 3—20 stamens crowded on a pilose receptacle adnate to the base of a nearly sessile ovate acute coriaceous scale longer than the stamens; filaments short, slender, 2-branched, each branch bearing a 1-celled oblong yellow half-anther hairy at the apex; pistillate in lax semi-erect aments terminal on leafy branches of the year, in pairs at the base of an ovate acute leafy deciduous scale, each flower subtended by a small acute bract with two minute bractlets at its base; calyx adnate to the ovary and dentate on the free narrow border. Nut ovoid, acute, compressed, conspicuously longitudinally ribbed, bearing at the apex the remnants of the calyx, marked on the broad base by a large pale scar and separating at maturity in the autumn from the leaf-like 3-lobed conspicuously serrate green involucre formed by the enlargement of the bract and bractlets of the flower and inclosing only the base of the nut, fully grown at mid-summer and loosely imbricated into a long-stalked open cluster. (Eucarpinus.)
Carpinus is confined to the northern hemisphere, and is distributed from the Province of Quebec through the eastern United States to the highlands of Central America in the New World, and from Sweden to southern Europe, Asia Minor, the temperate Himalayas, Korea, southern China, Japan and Formosa in the Old World. Fifteen or sixteen species are recognized. Of the exotic species, the European and west Asian Carpinus Betulus L. is frequently planted as an ornamental tree in the northeastern United States, where some of the species of eastern Asia promise to become valuable.
Carpinus is the classical name of the Hornbeam.
1. [Carpinus caroliniana] Walt. Hornbeam. Blue Beech.
Leaves often somewhat falcate, long-pointed, sharply doubly serrate with stout spreading glandular teeth, except at the rounded or wedge-shaped often unequal base, pale bronze-green, and covered with long white hairs when they unfold, at maturity thin and firm, pale dull blue-green above, light yellow-green and glabrous or puberulous below, with small tufts of white hairs in the axils of the veins, 2′—4′ long, 1′—1¾′ wide, with a slender yellow midrib, numerous slender veins deeply impressed and conspicuous above, and prominent cross veinlets; turning deep scarlet and orange color late in the autumn; petioles slender, terete, hairy, about ⅓′ long, bright red while young; stipules ovate-lanceolate, acute, pubescent, hairy on the margins, bright red below, light yellow-green at the apex, ⅓′ long. Flowers: staminate aments 1½′ long when fully grown, with broadly ovate acute boat-shaped scales green below the middle, bright red above; pistillate aments ½′—¾′ long, with ovate acute hairy green scales; styles scarlet. Fruit: nut ⅓′ long, its involucre short-stalked, with one of the lateral lobes often wanting, coarsely serrate, but usually on one margin only of the middle lobe, 1′—1½′ long, nearly 1′ wide, crowded on slender terete pubescent red-brown stems 5′—6′ in length.
A bushy tree, rarely 40° high, with a short fluted trunk occasionally 2° in diameter, long slightly zigzag slender tough spreading branches pendulous toward the ends, and furnished with numerous short thin lateral branches growing at acute angles, and branchlets at first pale green coated with long white silky hairs, orange-brown and sometimes slightly pilose during the summer, becoming dark red and lustrous during their first winter and ultimately dull gray tinged with red. Winter-buds ovoid, acute, about ⅛′ long, with ovate acute chestnut-brown scales white and scarious on the margins. Bark light gray-brown, sometimes marked with broad dark brown horizontal bands, 1/16′—⅛′ thick. Wood light brown, with thick nearly white sapwood; sometimes used for levers, the handles of tools, and other small articles.