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 pentandra in white down which aids wind dispersal. The scientific name refers to the male flowers having five stamens. The English name derives from the resemblance of the leaves to those of the bay laurel; other common names include bay-leaved willow and laurel willow. Its glossy leaves make it more decorative than many other willows, so it is often planted as an ornamental tree. It has become locally naturalised in northern North America, and is known as laurel willow there. Salix pentandra Salix pentandra, the bay willow, is a species of willow native to northern Europe and northern Asia. It is