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 atrocinerea Salix atrocinerea Salix atrocinerea, commonly called grey willow or large gray willow, is a species of willow. It is a bush or small tree up to tall. As a pioneer species of willow, it quickly colonizes poor soils. The grey willow distribution is mostly Atlantic from Western Europe and North Africa to some Mediterranean islands, and in North Africa. Naturally growing in Britain, France, Belgium, Spain, Portugal, Morocco, Tunisia, it is very common in the Iberian Peninsula, and is also found in Corsica. The species hybridizes readily with other species of willow and many hybrids have been identified. It flowers