Salix babylonica but beyond China, it has not generally been as successfully cultivated as some of its hybrid derivatives, being sensitive to late-spring frosts. In the more humid climates of much of Europe and eastern North America, it is susceptible to a canker disease, willow anthracnose ("Marssonina salicicola"), which makes infected trees very short-lived and unsightly. "Salix babylonica" (Babylon willow) has many cultivars, including: Various cultivars of "Salix matsudana" (Chinese willow) are now often included within "Salix babylonica", treated more broadly, including: Yet other weeping willow cultivars are derived from interspecific "Salix" hybrids, including "S. babylonica" in their parentage. The most widely
Salix humboldtiana Salix humboldtiana Salix humboldtiana, the Humboldt's willow, is a tree species of willow native to North and South America, growing along watercourses. The species is evergreen or deciduous, depending on climate. It can grow up to 25 meters tall, with a narrow triangular or columnar crown shape. The trunk has a maximum d.b.h. of 80 cm and dark brown to gray fissured bark. Narrow lanceolate leaves up to 15 cm long, with serrate margin and light green color, in temperate climates, it turns yellow in autumn. Catkins 4–10 cm long; male flowers yellowish green, with an ovate-lanceolate bract, six stamens;