What is white willow bark? There are many different kinds of trees and bushes in Europe, Asia, and some parts of North America that belong to the willow family. White willow, also called European willow (Salix alba), black willow, also called pussy willow (Salix nigra), crack willow (Salix fragilis), purple willow, also called weeping willow (Salix purpurea), and weeping willow are some of the more well-known species (Salix babylonica). Not all willow species store enough salicin to be used as a medicine. In one study, the amount of salicin after 1 and 2 years of growth in the fall and spring varied from 0.8% to 12.6%. Most of the time, the willow bark sold in Europe and the United States comes from white, purple, and crack willows. White Willow Bark Benefits: ◉ May relieve pain. ◉ Possibly anti-inflammatory properties. ◉ May reduce fever. ◉ May Ease Menstruation. Buy it from the natural health food store in the USA - Alive Herbals.