Plants deciduous trees; buds with several unequal scales. Leaves alternate, petiolate, often dimorphic; petioles usually long, terete or flattened; blade blade entire or lobed, linear to rhombic-ovate, margins dentate to serrate. Inflorescences elongate, cylindrical, pedunculate catkins, maturing before the leaves. Flowers pedicellate, subtended by a laciniate or toothed bract, disk cup-shaped; stamens 4-many, filaments free; ovaries sessile, solitary, 1-celled, surrounded at the base or up to 3/4 their length by the cup-shaped disk, with 2-4 parietal placentas; ovules many on each placenta; style short, with 2-4 branches. Capsules 2-4-valved; seeds minute, numerous, with a dense tuft of long, silky hairs.
Populus includes about 100 species, all native to north temperate regions of the world.