Description
The active ingredient in white willow is salicin, which the body converts into salicylic acid. The first aspirin (acetylsalicylic acid) was made from a different salicin-containing herb, meadowsweet, working in essentially the same way.
The bark of the stately white willow tree (Salix alba) has been used in China for centuries and early settlers to America found Native Americans gathering bark from indigenous willow trees for similar purposes.