Trees up to 20 m. Branchlets nearly 4-angled, glabrous to tomentose; buds broadly ovoid, scurfy to tomentose, becoming dark brown when dry. Leaves 25-35 cm; petiole 5-10 cm; axis grooved to subterete, glabrous or pilose; leaflets 7-9; petiolule 0-2 mm, sparingly to densely tomentose; leaflet blade lanceolate to ovate-oblong, 5-18 × 2-6 cm, papery, glabrous or villous along veins abaxially, base rounded to attenuate, margin crenate, apex acuminate; primary veins 2-16 on each side of midrib. Panicles terminal and lateral, 8-20 cm, lax. Flowers polygamodioecious, appearing after leaves. Pedicel ca. 2 mm. Calyx cupular, membranous, 1-1.5 mm; teeth truncate or broadly deltate. Corolla white; lobes linear-spatulate, ca. 3 mm. Stamens of staminate flowers equal to or slightly longer than corolla lobes, those of bisexual flowers exceeding corolla lobes. Samara linear-spatulate, 2.5-3 cm × ca. 4 mm; wing decurrent to upper part of nutlet. Fl. May-Jul, fr. Sep-Oct.

* Slopes, forests in valleys; 400-1100 m. Hubei, Hunan, Shaanxi