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 orestera Salix orestera Salix orestera is a species of willow known by the common name Sierra willow, or gray-leafed Sierra willow. It is native to the Sierra Nevada of California and western Nevada, where it grows in moist areas in high mountain subalpine and alpine climates. It can also be found in Oregon. "Salix orestera" is very similar to "Salix glauca" and is sometimes included within that species. It is a shrub reaching one half to two meters tall, bushy with slender branches. The lance-shaped leaves are up to 9.5 centimeters long and often have coatings of silky hairs. The inflorescence