Willow are very cross-compatible, and numerous hybrids occur, both naturally and in cultivation. A well-known ornamental example is the weeping willow ("Salix × sepulcralis"), which is a hybrid of Peking willow ("Salix babylonica") from China and white willow ("Salix alba") from Europe. The hybrid cultivar 'Boydii' has gained the Royal Horticultural Society's Award of Garden Merit. Numerous cultivars of "Salix" L. have been developed and named over the centuries. New selections of cultivars with superior technical and ornamental characteristics have been chosen deliberately and applied to various purposes. Most recently, "Salix" has become an important source for bioenergy production and for
Salix boothii Salix boothii Salix boothii is a species of willow known by the common name Booth's willow. It is native to western North America from British Columbia and Alberta south to California and New Mexico. It grows in moist mountain habitat, such as riverbanks. "Salix boothii" is a shrub which can reach in height. It is larger and has more branches in well-drained soils, and takes a smaller, simpler form in saturated areas such as bogs. The leaves are lance-shaped to oval with a pointed tip and smooth-edged or lightly serrated. They are up to 10 cm long when mature with