A family of dicotyledonous (see dicotyledon) trees and shrubs that have alternate, deciduous, simple leaves with stipules and tiny flowers, in unisexual catkins which are borne on separate male and female plants. The flowers have no perianth, merely a basal bract, and have either 2 to many stamens, or a 1-celled, bicarpellary ovary with 2 stigmas. The trees are mainly wind-pollinated. The fruits are capsules, and the seeds bear long, silky hairs, which help in wind dispersal. Some are important timber trees. There are two genera (Salix and Populus), comprising 330–50 species, most occurring in the northern temperate zone.
Subjects: Plant Sciences and Forestry.