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
Phyllonorycter salicifoliella Phyllonorycter salicifoliella Phyllonorycter salicifoliella is a moth of the Gracillariidae family. It is widespread across North America, from Mississippi to Ontario in the east and from southern California to northern British Columbia in the west. The length of the forewings is 3–4 mm. Adults are on wing from July to mid-August and again from late August to November in two generations. The larvae mostly feed on "Salix" species, including "Salix alba", "Salix amygdaloides", "Salix babylonica", "Salix bebbiana", "Salix bonplandiana", "Salix caroliniana", "Salix eriocephala", "Salix lasiolepis", Salix "longifolia", "Salix lutea", "Salix monticola", "Salix purpurea", "Salix x rubens" ("Salix alba" x "Salix