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 alaxensis Salix alaxensis Salix alaxensis is a species of flowering plant in the willow family known by the common names Alaska willow and feltleaf willow. It is native to northern North America, where it occurs throughout northern Canada and Alaska. This plant is a shrub or tree up to tall. The stem diameter is up to . In harsher climates, it remains much smaller. The smooth, gray bark becomes furrowed and scaly with age. The leaves are up to 11 cm long and have woolly undersides. The species is dioecious, with male and female reproductive parts on separate individuals. The inflorescence