Ulmus americana, generally known as the American elm or, less commonly, as the white elm or water elm, is a species native to eastern North America, naturally occurring from Nova Scotia west to Alberta and Montana, and south to Florida and central Texas. The American elm is an extremely hardy tree that can withstand winter temperatures as low as −42 °C (−44 °F). Trees in areas unaffected by Dutch elm disease can live for several hundred...
Trees , 21-35 m; crowns spreading, commonly vase-shaped. Bark light brown to gray, deeply fissured or split into plates. Wood soft. Branches pendulous, old-growth branches smooth, not winged; twigs brown, pubescent to glabrous. Buds brown, apex acute, glabrous; scales reddish brown, pubescent. Leaves: petiole ca. 5 mm, glabrous to pubescent. Leaf blade oval to oblong-obovate, 7-14 × 3-7 cm, base oblique, margins doubly serrate, apex acute to acuminate; surfaces abaxially glabrous to slightly pubescent, tufts in axils of veins, adaxially glabrous to scabrous. Inflorescences fascicles, less than 2.5 cm, flowers and fruits drooping on elongate pedicels; pedicel 1-2 cm. Flowers: calyx shallowly lobed, slightly asymmetric, lobes 7-9, margins ciliate; stamens 7-9; anthers red; stigmas white-ciliate, deeply divided. Samaras yellow-cream when mature, sometimes tinged with reddish purple (s range of species), ovate, ca. 1 cm, narrowly winged, margins ciliate, cilia yellow to white, to 1 mm. Seeds thickened, not inflated. 2 n = 56.
Family | other |
---|