Calyx bell-shaped, 4–9-cleft. Stamens 4–9, with long and slender filaments. Ovary 1–2-celled, with a single anatropous ovule suspended from the summit of each cell; styles 2, short, diverging, stigmatic along the inner edge. Fruit a 1-celled and 1-seeded membranaceous samara, winged all around. Albumen none; embryo straight; the cotyledons large.—Flowers polygamous, purplish or yellowish, in lateral clusters, in our species preceding the leaves, which are strongly straight-veined, short-petioled, and oblique or unequally somewhat heart-shaped at base. Stipules small, caducous. (The classical Latin name.)
[*] Flowers nearly sessile; fruit orbicular, not ciliate; leaves very rough above.
1. U. fúlva, Michx. (Slippery or Red Elm.) Buds before expansion soft-downy with rusty hairs (large); leaves ovate-oblong, taper-pointed, doubly serrate (4–8´ long, sweet-scented in drying), soft-downy beneath or slightly rough downward; branchlets downy; calyx-lobes and stamens 5–9; fruit (8–9´´ wide) with the cell pubescent.—Rich soil, N. Eng. to Dak., and southward. March, April.—A small or middle-sized tree (45–60° high), with tough reddish wood, and a very mucilaginous inner bark.
[*][*] Flowers on slender drooping pedicels, which are jointed above the middle; fruit ovate or oval, fringed-ciliate; leaves smooth above, or nearly so.
2. U. Americàna, L. (American or White Elm.) Buds and branchlets glabrous; branches not corky; leaves obovate-oblong or oval, abruptly pointed, sharply and often doubly serrate (2–4´ long), soft-pubescent beneath, or soon glabrous; flowers in close fascicles; calyx with 7–9 roundish lobes; fruit glabrous except the margins (½´ long), its sharp points incurved and closing the notch.—Moist woods, especially along rivers, in rich soil. April.—A large and well-known ornamental tree, variable in habit, usually with spreading branches and drooping branchlets.
3. U. racemòsa, Thomas. (Cork or Rock Elm.) Bud-scales downy-ciliate and somewhat pubescent, as are the young branchlets; branches often with corky ridges; leaves nearly as in the last, but with veins more simple and straight; flowers racemed; fruit much as in the last, but rather larger.—River-banks, S. W. Vt. to Ont. and central Minn., south to Mo. and Ky. A large and very valuable tree.
4. U. alàta, Michx. (Wahoo or Winged Elm.) Bud-scales and branchlets nearly glabrous; branches corky-winged, at least some of them; leaves downy beneath, ovate-oblong and oblong-lanceolate, acute, thickish, small (1–2½´ long); calyx-lobes obovate; fruit downy on the face at least when young.—Va. to S. Ind., S. Mo., and southward. March. A small tree.
2. PLÁNERA, Gmelin. Planer-tree.
Flowers monœciously polygamous. Calyx 4–5-cleft. Stamens 4–5. Ovary ovoid, 1-celled, 1-ovuled, crowned with 2 spreading styles which are stigmatose down the inner side, in fruit becoming coriaceous and nut-like, not winged. Albumen none; embryo straight.—Trees with small leaves, like those of Elms, the flowers appearing with them, in small axillary clusters. (Named for J. J. Planer, a German botanist.)
1. P. aquática, Gmel. Nearly glabrous; leaves ovate-oblong, small; fruit stalked in the calyx, beset with irregular rough projections.—Wet banks, N. C. to Ky., S. Ill., and southward. April. A rather small tree.