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 bonplandiana Salix bonplandiana Salix bonplandiana (Bonpland willow), (Span.: "ahuejote", "sauce", "ahujote", and "huejote"), is a perennial species of willow tree native to southern and southwest Mexico and extending into central Guatemala; in western Mexico it is a tree of the Sierra Madre Occidental cordillera, but also occurring in other small locales, for example Baja California Sur, northern Sonora, San Luis Potosi, etc. A core disjunct area occurs in central and southeast Arizona, in advantageous locales, especially associated with higher elevations and water. In Mexico, the Bonpland willow is associated with the Pacific Coast, and in southern Mexico, the range extends into