Tall trees. Buds mostly resiniferous, covered with scales. Leaves alternate, petiolate, broad, oblong to ovate or rhombic; stipules membranous, small, narrow. Catkins loose, appearing before leaves, the staminate ones mostly pendulous. Bracts generally lobed or incised, sometimes crenate. Pedicels distinct. Perianth reduced to a cup-like nectariferous disk. Stamens 4-30, even more; filaments free; anthers 2-celled, oblong to ovate. Ovary mostly sessile or subsessile, 1-celled, many-ovuled; style short; stigmas 2, entire or lobed. Capsule 2-3 (-4)-valved. Seeds small, many, ovoid or obovoid, with a tuft of long silky hairs arising from the funicle, dispersed by wind.