White willow, also known as European willow, is one of several willow species that are distributed throughout Europe, northern Africa and central Asia. Introduced to the New World by 18th century Europeans, the tree is now naturalized in North America.
For centuries the white willow bark has been used as an analgesic. In fact, there is recorded evidence that the herb was used for this purpose in China as early as 500 B.C. The herb was also used extensively by Native Americans for fever and pain associated with arthritis. Today, we know that its effectiveness is due to a chemical called salicin that is converted in the human body into acetylsalicylic acid, a compound better known as aspirin.
