Trees, to 25 m tall, d.b.h. to 1 m, deciduous. Bark dark gray, irregularly longitudinally fissured. Branchlets yellowish gray, glabrous or pubescent, unwinged and without a corky layer, with scattered lenticels. Winter buds dark brown to red-brown, ± globose to ovoid; inner bud scale margin usually white ciliate. Petiole 4-10 mm, pubescent; leaf blade elliptic-ovate to elliptic-lanceolate, 2-8 × 1.2-3.5 cm, abaxially pubescent when young but glabrescent or with tufts of hairs in vein axils or sometimes a few hairs on midvein and in forks of secondary veins, adaxially glabrous, base obliquely to symmetrically obtuse to rounded, margin simply or sometimes doubly serrate, apex acute to acuminate; secondary veins 9-16 on each side of midvein. Inflorescences fascicled cymes on second year branchlets, appearing before leaves. Perianth 4-lobed, margin ciliate. Samaras whitish tan, ± orbicular to rarely broadly obovate or elliptical, 1-2 × 1-1.5 cm, glabrous except for pubescence on stigmatic surface; stalk 1-2 mm; perianth persistent. Seed at center of samara or occasionally slightly toward apex but not reaching the apical notch. Fl. and fr. Mar-May. 2n = 28.
Trees , 15 to 30 m; crowns open. Bark gray to brown, deeply furrowed with interlacing ridges. Wood brittle. Branches not winged; twigs gray-brown, pubescent. Buds dark brown, ovoid, glabrous; scales light brown, shiny, glabrous to slightly pubescent. Leaves: petiole 2-4 mm, glabrous. Leaf blade narrowly elliptic to lanceolate, 2-6.5 × 2-3.5 cm, base generally not oblique, margins singly serrate, apex acute; surfaces abaxially with some pubescence in axils of veins, adaxially glabrous; lateral veins forking to 3 times per side. Inflorescences tightly clustered fascicles, 6-15-flowered, 0.5 cm, flowers and fruits not pendulous, sessile. Flowers: calyx shallowly lobed, lobes 4-5, glabrous; stamens 4-8; anthers brownish red; stigmas green, lobes exserted. Samaras yellow-cream, orbiculate, 10-14 mm diam., broadly winged, glabrous, tip notched 1/3-1/2 its length. Seeds thickened, not inflated. 2 n = 28.