The Willow Family

The family Salicaceae, also known as the willow family, are a family of flowering plants, many of which are trees, and which family include the aspen, cottonwoods, poplar and willow trees. Within this family are found 56 gernera with about 1220 speciea.

The traditional family (Salicaceae sensu stricto) includes only the willows and poplars. However, genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly expanded the circumscription of the family to include the cottonwoods, the aspens as well as the tropical Scyphostegiaceae and many of the former Flacourtiaceae.

Most members of the Salicaceae family are trees or shrubs that have simple leaves with alternate arrangement, and temperate members are usually deciduous. Most members have serrate or dentate leaf margins, and many of those that have such toothed margins exhibit salicoid teeth.

A salicoid tooth is one in which a vein enters the tooth, expands, and terminates at or near the apex, near which are spherical and glandular protuberances called setae.

Sometimes the glands will deflate and appear torus (doughnut) shaped. Some members of the family exhibit violoid or theoid teeth, characters along with presence of an aril and introrse anther dehiscence that are sometimes used to split the family into three families, Salicaceae sensu medio, Samydaceae, and Scyphostegiaceae.

Members of the family often have flowers which are reduced and inconspicuous, and all have ovaries that are superior or half-inferior with parietal placentation.

The Salicaceae family thrives in moist and wet areas, particularly in temperate regions of the Northern Hemisphere. They are often found in riparian habitats like streams, lakes, and marshes, and can also be found at higher elevations in mountain meadows.

The Salicaceae family has a wide global distribution. It is most common in the temperate and subarctic regions of the Northern Hemisphere, particularly in northern, alpine, and arctic areas. However, it also extends into subtropical and tropical areas, and many species thrive in wet or moist habitats like wetlands, along streams, and rivers.

The two main genera are Salix (willows) and Populus (poplars), which are widely distributed, particularly in temperate regions.