Numerous plants contain natural aspirin-type chemicals called salicylates, and aspirin itself was originally isolated from plant sources. In fact, the name aspirin comes from the word, spiraea, the old botanical genus name for meadowsweet. The word salicylate derives from salix, the Latin name for willow. Herbs with significant quantities of salicylates have a marked anti-inflammatory effect, without the dangers posed by aspirin to the stomach.
Other plants that contain such constituents include the bark of willow (Salix spp.), winter-green (Gaultheria procumbens), birch (Betula spp.), and many poplars and aspens (such as Populus tremuloides). This group of herbs is most useful for inflammations of muscles, bones, and connective tissue caused by sports injuries and conditions such as osteoarthritis. The pain relieving and fever-lowering actions of these herbs are believed to be due to the salicylates present in the herbs. Salicylates are also believed to suppress the synthesis of natural inflammatory chemicals produced by the body, thereby reducing inflammation. Unlike aspirin, willow preparations do not work in the same way, suggesting different mechanisms than those associated with salicylates. Because of this, willow bark cannot be used as a substitute for aspirin in preventive thrombolytic protocols against strokes and heart attacks.