Habit varying from a small much-branched shrub to a forest tree 15 m tall, almost invariably dioecious; branchlets subglabrous (apart from the glands) to densely hairy. Leaf-blades usually elliptic-oblanceolate to elliptic-obovate, less commonly lanceolate, ovate or elliptic-oblong, 1.5–13(–17) cm long, 0.6–6 cm wide, pointed to rounded at the apex, broadly cuneate to rounded, truncate or slightly cordate and mostly unequal-sided at the base, entire to coarsely and rather distantly serrate (sometimes biserrate on sterile shoots), glabrous to sparsely or less often quite densely hairy particularly on the midrib, covered with golden-yellow glands on both surfaces at first and rather persistently so beneath; pock-marked when the glands wither; primary lateral nerves (4–)8–18 on either side, fine but usually visible on both surfaces; petiole 1–16 mm long. Male catkins dense or rather lax, the flowers then often irregularly grouped into clusters, 0.5–3.5 cm long; bracts subtending 1(–2) flowers, variously shaped (see below), 1–2(–3) mm long, glandular, ciliate to densely hairy outside; stamens mostly 5–10. Female catkins becoming lax, often from an early stage, 1–3.5 cm long and up to 6 cm long in fruit; bracts ovate-triangular, sometimes broadly so, rarely ± lanceolate, 0.8–2 mm long, ciliate to hairy overall; bracteoles usually 4, variously oblong-elliptic to broadly spathulate or suborbicular, concave, 0.4–1 mm long; style-arms linear and ± terete to linear-lanceolate, flattened and often somewhat serrate, 0.8–3 mm long. Fruits brown to greyish white, ellipsoid-globose to subglobose, 3–4 mm long, 1.8–4 mm wide.
