Trees to 35 m tall; bark dark red-brown, exfoliating in thin flakes. Branches red-brown, glabrous; branchlets brown, densely resinous glandular and pubescent. Petiole 0.8-2 cm; leaf blade ovate, ovate-elliptic, or oblong, 4-9 × 2.5-6 cm, abaxially densely resinous punctate and pubescent, bearded in axils of lateral veins, adaxially densely villous when young, base rounded or subcordate, margin irregularly and doubly mucronate serrate, apex acuminate or caudate-acuminate; lateral veins 8-14 on each side of midvein. Female inflorescence 1, or 2 or 3 in a raceme, pendulous, oblong-cylindric, 3-5 cm × 7-12 mm; peduncle 0.5-1.5 cm; bracts 5-8 mm, pubescent, ciliate, 3-lobed, middle lobe lanceolate, lateral lobes ovate, ca. 1/3 as long as middle lobe. Nutlet obovate, 2-3 × 1.5-2 mm, with membranous wings ca. as wide as nutlet. Fl. Jun-Jul, fr. Jul-Aug. 2n = 56.
Trees or small shrubs, 2-15 m tall. Bark peeling horizontally, white, brownish or reddish-white. Young shoots pubescent, older glabrescent. Leaves ovate or rhomboid, 2.5-8.2 cm x 1.8-6.2 cm, base rounded, subcordate or cuneate, margin doubly serrate to sub-serrate, the surface sparsely pilose, often villous at the angles of the veins on the under surface; acute or acuminate; nerve pairs 6-9(-11). Petiole 0.9-2 cm long, pilose to pubescent. Male flowers in catkins 3-3.7 cm x c.4 mm. Bract broadly ovate-obtuse, c. 1.7 mm long, pubescent on the inside; bracteoles more or less naviculate, c. 1.2 mm long, ciliate. Filament inconspicuously forked, anthers c. the size of the bracteoles, oblong, sometimes aristate at the tip. Strobili 2.5-4 cm x c. 1.2 cm. Styles variable in size. Fruiting scale 8-9 mm long, woody, lobes minutely ciliate; median lobe 4-5 mm long, linear-lanceolate, longer than the 2 erect or outspread laterals. Nut elliptic—ovate, 2.5-3 mm long, as broad as or broader than the wing. Wing sometimes with 1-2 linear appendages at the apex.