Trees to 30 m tall; bark grayish white, smooth, becoming dark gray, furrowed; crown ovoid. Old branches grayish brown, glabrous; branchlets slender or robust, dull reddish brown pubescent. Buds conical, viscid, glabrous. Petiole very laterally flattened, 2-8(-12) cm, tomentose or downy; leaf blade ovate-orbicular or ovate, 5-15 × 4-7(-13) cm, abaxially grayish green, densely pubescent when young, adaxially dark green, glabrous or downy along veins, shiny, base truncate or cordate, rarely subrounded or cuneate, with 2 raised glands, margin incurved, glandular crenate-serrate or loosely or coarsely dentate, apex long acuminate or caudate. Male catkin 6-10 cm. Male flower: disc dentate-lobed. Fruiting catkin 12-20(-30) cm; rachis pilose; bracts palmatiparted, brown, obovate-elliptic, ca. 2.5 mm, ciliate. Capsule long ovoid-ellipsoid, (2-)4-6 mm, glabrous, 2-valved, shortly stipitate, apex acute. Seeds dark. Fl. Mar-Apr, fr. Apr-May.