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 discolor Salix discolor Salix discolor, the American pussy willow or glaucous willow, is a species of willow native to North America, one of two species commonly called pussy willow. It is native to the vast reaches of Alaska as well as the northern forests and wetlands of Canada (British Columbia east to Newfoundland), and is also found in the northern portions of the contiguous United States (Idaho east to Maine, and south to Maryland). It is a weak-wooded deciduous shrub or small tree growing to tall, with brown shoots. The leaves are oval, 3–14 cm long and 1-3.5 cm broad, green