'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. It is a medium- to large-sized deciduous tree, growing up to 20–25 m (66–82 ft) tall. It grows rapidly, but has a short lifespan, between 40 and 75 years.

Early Chinese cultivar selections include the original weeping willow in which the branches and twigs are strongly pendulous, which was presumably spread along ancient trade routes. These distinctive trees were subsequently introduced into England from Aleppo in northern Syria in 1730, and have rapidly become naturalised, growing well along rivers and in parks. These plants are all females, readily propagated, and capable of being inter bred with various other kinds of willows, but not breeding true from seed.

Some believe the ‘weeping’ refers to the way raindrops stream down the branches, dripping ‘tears’ from the tips. Therefore, this willow is a beloved tree in cemeteries and memorial gardens.

More Info: en.wikipedia.org