Trees, or rarely shrubs, with deeply furrowed bark, branchlets often furnished with corky wings, and buds with numerous ovate rounded chestnut-brown scales closely imbricated in two ranks, increasing in size from without inward, the inner accrescent, replacing the stipules of the first leaves, deciduous, marking the base of the branchlet with persistent ring-like scars. Leaves simply or doubly serrate; stipules linear, lanceolate to obovate, entire, free or connate at base, scarious, inclosing the leaf in the bud, caducous. Flowers from axillary buds near the ends of the branches similar to but larger than the leaf-buds, the outer scales sterile, the inner bearing flowers and rarely leaves. Flowers perfect, jointed on slender bibracteolate pedicels from the axils of linear acute scarious bracts, in pedunculate or subsessile fascicles or cymes sometimes becoming racemose, appearing in early spring before the leaves in the axils of those of the previous year, or autumnal in the axils of leaves of the year; calyx campanulate, 5—9-lobed, membranaceous, marcescent; stamens 5 or 6 inserted under the ovary; filaments filiform or slightly flattened, erect in the bud, becoming exserted; anthers oblong, emarginate, and subcordate; ovary sessile or stipitate, compressed, crowned by a simple deeply 2-lobed style, the spreading lobes papillo-stigmatic on the inner face, usually 1-celled by abortion, rarely 2-celled; ovule amphitropous; micropyle extrorse, superior. Fruit an ovoid or oblong, often oblique, sessile or stipitate samara surrounded at base by the remnants of the calyx, the seminal cavity compressed, slightly thickened on the margin, chartaceous, produced into a thin reticulate-venulose membranaceous light brown broad or rarely narrow wing naked or ciliate on the margin, tipped with the remnants of the persistent style, or more or less deeply notched at apex, and often marked by the thickened line of the union of the two carpels. Seed ovoid, compressed, without albumen, marked on the ventral edge by the thin raphe; testa membranaceous, light or dark chestnut-brown, of two coats, rarely produced into a narrow wing; embryo erect; cotyledons flat or slightly convex, much longer than the superior radicle turned toward the oblong linear pale hilum.
Ulmus, with eighteen or twenty species, is widely distributed through the boreal and temperate regions of the northern hemisphere with the exception of western North America, reaching in the New World the mountains of southern Mexico and in the Old World the Sikkim Himalaya, western China, and Japan. Of the exotic species, Ulmus procera Salisb., the so-called English Elm, and Ulmus glabra, Huds., the Scotch Elm, and several of its varieties, have been largely planted for shade and ornament in the north Atlantic states, where old and large specimens of the former can be seen, especially in the neighborhood of Boston.
Ulmus produces heavy, hard, tough, light-colored wood, often difficult to split. The tough inner bark of some of the species is made into ropes or woven into coarse cloth, and in northern China nourishing mucilaginous food is prepared from the inner bark.
Ulmus is the classical name of the Elm-tree.
CONSPECTUS OF THE NORTH AMERICAN SPECIES.
Flowers vernal, appearing before the leaves. Flowers on slender drooping pedicels; fruit ciliate on the margins. Wing of the fruit broad. Bud-scales and fruit glabrous; branchlets destitute of corky wings; leaves obovate-oblong to elliptic, usually smooth on the upper, soft-pubescent on the lower surface.1. [U. americana] (A, C). Bud-scales puberulous; branches often furnished with corky wings; fruit hirsute; leaves obovate to oblong, smooth on the upper, soft-pubescent on the lower surface.2. [U. racemosa] (A). Wing of the fruit narrow; bud-scales glabrous or slightly puberulous; branchlets usually furnished with broad corky wings; fruit hirsute, leaves ovate-oblong to oblong-lanceolate, smooth on the upper, soft-pubescent on the lower surface.3. [U. alata] (A, C). Flowers on short pedicels; fruit naked on the margins; bud-scales coated with rusty hairs; fruit pubescent; leaves ovate-oblong, scabrous on the upper, pubescent on the lower surface.4. [U. fulva] (A, C). Flowers autumnal, appearing in the axils of leaves of the year; branchlets furnished with corky wings; fruit hirsute. Bud-scales puberulous; flowers on short pedicels; leaves ovate, scabrous on the upper, soft-pubescent on the lower surface.5. [U. crassifolia] (C). Bud-scales glabrous; flowers on long pedicels; leaves oblong to oblong-obovate, acuminate, glabrous on the upper, pale and puberulous on the lower surface.6. [U. serotina] (C).
1. [Ulmus americana] L. White Elm.
Leaves obovate-oblong to elliptic, abruptly narrowed at apex into a long point, full and rounded at base on one side and shorter and cuneate on the other, coarsely doubly serrate with slightly incurved teeth, when they unfold coated below with pale pubescence and pilose above with long scattered white hairs, at maturity 4′—6′ long, 1′—3′ wide, dark green and glabrous or scabrate above, pale and soft-pubescent or sometimes glabrous below, with a narrow pale midrib and numerous slender straight primary veins running to the points of the teeth and connected by fine cross veinlets; turning bright clear yellow in the autumn before falling; petioles stout, ¼′ in length; stipules linear-lanceolate, ½′—2′ long. Flowers on long slender drooping pedicels sometimes 1′ in length, in 3 or 4-flowered short-stalked fascicles; calyx irregularly divided into 7—9 rounded lobes ciliate on the margins, often somewhat oblique, puberulous on the outer surface, green tinged with red above the middle; anthers bright red; ovary light green, ciliate on the margins with long white hairs; styles light green. Fruit on long pedicels in crowded clusters, ripening as the leaves unfold, ovoid to obovoid-oblong, slightly stipitate, conspicuously reticulate-venulose, ½′ long, ciliate on the margins, the sharp points of the wings incurved and inclosing the deep notch.
A tree, sometimes 100°—120° high, with a tall trunk 6°—11° in diameter, frequently enlarged at the base by great buttresses, occasionally rising with a straight undivided shaft to the height of 60°—80° and separating into short spreading branches, more commonly divided 30°—40° from the ground into numerous upright limbs gradually spreading and forming an inversely conic round-topped head of long graceful branches, often 100° or rarely 150° in diameter, and slender branchlets frequently fringing the trunk and its principal divisions, light green and coated at first with soft pale pubescence, becoming in their first winter light reddish brown, glabrous or sometimes puberulous and marked by scattered pale lenticels, and by large elevated semiorbicular leaf-scars showing the ends of three large equidistant fibro-vascular bundles, later becoming dark reddish brown and finally ashy gray. Winter-buds ovoid, acute, slightly flattened, about ⅛′ long, with broadly ovate rounded light chestnut-brown glabrous scales, the inner bright green, ovate, acute, becoming on vigorous shoots often nearly 1′ in length. Bark 1′—1½′ thick, ashy gray, divided by deep fissures into broad ridges separating on the surface into thin appressed scales. Wood heavy, hard, strong, tough, difficult to split, coarse-grained, light brown, with thick somewhat lighter colored sapwood; largely used for the hubs of wheels, saddle-trees, in flooring and cooperage, and in boat and shipbuilding.