Salix (genus) en

Genus containing around 400 species of shrubs and trees primarily native to north temperate areas, valued for ornament, shade, erosion control, and timber. Leaves and bark of the willow tree have been used medicinally in ancient Assyria, Sumer, Egypt, Greece, and by Native Americans, as a remedy for aches and fever: willows contain salicin, a substance that chemically resembles aspirin when metabolized by the human body. Willow species easily form hybrids.