Description from Flora of China
Trees to 20 m tall; bark gray; crown large and spreading. Branchlets brown, terete, pilose and glabrescent or tomentose. Buds ovoid, large, ca. 2 cm, usually glabrous, rarely downy, ± viscid. Petiole terete, 5-12 cm, downy; leaf blade ovate-cordate, 10-15 × 8-12 cm, abaxially grayish green, downy at least along veins, adaxially dull green, glabrous, base cordate or rounded, margin glandular crenate, densely ciliate, apex acute to acuminate. Male catkin ca. 6 cm; rachis glabrous. Female catkin to 22 cm; rachis glabrous or pubescent. Capsule glabrous or pilose, 4-valved; stipe 5-10 mm or capsule subsessile. Fl. May, fr. Jun. 2n = 38.
Mountains, mixed woods, forests; 2200-3400 m. Xizang, Yunnan [Bhutan, India, Kashmir, N Myanmar, Nepal, Pakistan, Sikkim].