Trees with pale, ± furrowed bark. Winter buds with several imbricate scales. Lvs alternate; petiole usually long; stipules inconspicuous, caducous; lamina lanceolate-ovate to broad-ovate or deltoid, sometimes lanceolate in juvenile lvs, entire or dentate. Catkins pendulous, appearing before lvs. Fls anemophilous, each subtended by a bract; bract usually laciniate or toothed, rarely entire, quickly shrivelling. Perianth reduced to a cupular, oblique disc; glands 0. ♂ fls with 4-many stamens; filaments ± filiform; anthers generally red to purple, occasionally yellow. ♀ fls with short style; stigmas 2-4. Capsule 2-(4)-valved, often ripe before lvs are fully mature. Seeds numerous, minute.