50 tea bags - ZIN: 427627 - The white willow was introduced into the United States from Europe and can be found next to rivers and streams throughout the country. The bark is the part of the willow used, and is easily removed in the spring when the sap begins to flow. Willows have been used for centuries for pain support and reduction of . The leaves can be chewed, and contain salicylic acid. This compound has been synthesized into acetylsalicylic acid, otherwise known as aspirin. Natural salicylic acid is nearly as potent as aspirin, however, the compound salicin from willow does not cause gastric or intestinal upset or bleeding as aspirin can, This is because willow does not block prostaglandins in the stomach or intestines.