Salix babylonica Salix babylonica Salix babylonica (Babylon willow or weeping willow; ) is a species of willow native to dry areas of northern China, but cultivated for millennia elsewhere in Asia, being traded along the Silk Road to southwest Asia and Europe. "Salix babylonica" is a medium- to large-sized deciduous tree, growing up to tall. It grows rapidly, but has a short lifespan, between 40 and 75 years. The shoots are yellowish-brown, with small buds. The leaves are alternate and spirally arranged, narrow, light green, 4–16 cm long and 0.5–2 cm broad, with finely serrate margins and long acuminate tips; they turn
Salix fragilis also spreads by root suckers, expanding into pure 'groves'. "Salix fragilis" is cultivated as a fast-growing ornamental tree. The cultivar "Salix fragilis" 'Russelliana' (syn. "S. fragilis" var. "russelliana" (Sm.) Koch) is by far the most common clone of crack willow in Great Britain and Ireland, very easily propagated by cuttings. It is a vigorous tree commonly reaching tall, with leaves up to 15 cm long. It is a female clone. "S. fragilis" has escaped cultivation to become an invasive species in various parts of the world, including: New Zealand; the upper half of the United States; and South Africa. In