the Russian willow expert Alexey Skvortsov. The only reported difference between the two species is S. matsudana has two nectaries in each female flower, whereas S. babylonica has only one; however, this character is variable in many willows (for example, crack willow, Salix × fragilis, can have either one or two), so even this difference may not be taxonomically significant. A horticultural variant with twisted twigs and trunk, the corkscrew willow (S. matsudana var. tortuosa), is widely planted. Cultivation Salix babylonica, especially its pendulous-branched ("weeping") form, has been introduced into many other areas, including Europe and the southeastern United States, 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. Cultivars Salix babylonica (Babylon willow) has many cultivars, including: 'Babylon' (synonym: 'Napoleon') is the most widely grown cultivar of S. babylonica, with its typical weeping branches. 'Crispa' (synonym: 'Annularis') is a mutant of 'Babylon', with spirally curled leaves. Various cultivars of Salix matsudana (Chinese willow) are now often included within Salix babylonica, treated more broadly, including: 'Pendula' is one of the best weeping trees, with a silvery shine, hardier, and more disease resistant. 'Tortuosa' is an upright tree with twisted and contorted branches, marketed as corkscrew willow. Yet other weeping willow cultivars are derived from interspecific Salix hybrids, including S. babylonica in their parentage. The most widely grown weeping willow cultivar is Salix × sepulcralis 'Chrysocoma', with bright yellowish branchlets. Uses Peking willow is a popular ornamental tree in northern China, and is also grown for wood production and shelterbelts there, being particularly important around the oases of the Gobi Desert, protecting agricultural land from desert winds. Origin The epithet babylonica in this Chinese species' scientific name (S. babylonica), as well as the related common names "Babylon willow" or "Babylon weeping willow", derive from a misunderstanding by Linnaeus that this willow was the tree described in the Bible in the opening of Psalm 137 (here in Latin and English translations): From the Clementine Vulgate (Latin, 1592): Super flumina Babylonis illic sedimus et flevimus, cum recordaremur Sion. In salicibus in medio ejus suspendimus organa nostra.... Here, "salicibus" is the dative plural of the Latin noun salix, the