From Tolkien Gateway

Willows were waterside trees that grew throughout Middle-earth. The most famous of these was the ancient tree known as Old Man Willow, on the banks of the Withywindle in the Old Forest.[1]

In Beleriand was the region Nan-tathren, a wooded vale which took its name from the willow trees that grew there.[2]

Other names[edit]

The Sindarin name for "willow" is tathar.[3]

External links[edit]

Willow at Wikipedia