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 acutifolia Salix acutifolia Salix acutifolia, also known as Siberian violet-willow, long-leaved violet willow or sharp-leaf willow, is a species of flowering plant in the Salicaceae family, native to Russia and eastern Asia. It is a spreading, deciduous shrub or tree, growing to tall by wide. The young shoots are deep purple with a white bloom. The leaves are narrow, up to long. The catkins are produced in early spring, before the leaves. Older bark has a fine, netted pattern. Like all willows this species is dioecious. Male catkins are and silvery, with gold anthers, while female catkins are green and long.