The Salicaceae or Willow family as it is commonly called is a small world-wide family of perennial woody, flowering plants consisting of trees and shrubs. This is a small family with only about 54 genera approximately 1,200 species. In North America there are only 2 genera, Populus and Salix, which includes the willows, poplars, aspens and cottonwoods.
Salicaceae is native to mostly temperate regions within the northern hemisphere with greatest diversities toward the northern limits. Preferred habitats are riparian areas such as streams, lakes and other moist or wet areas, mostly in higher elevations especially mountains and mountain meadows.
Common family characteristics include the ability to grow fast, reproduce asexually through root shoots and ability to form clonal colonies. North American species are all trees. Flowers are mostly unisexual often with male and female flowers on different trees, some flowers developing before leaves. Leaves are usually deciduous but some are persistent (Cottonwoods), leaves alternate, margins simple with toothed or serrated. inflorescences are typically catkins. Fruit are catkins with nectar. Pollination may include insects or wind. Low economic importance includes commercially grown ornamentals such as willows, aspens and cottonwood trees.