Wintergreen is an evergreen undershrub, native to Canada, growing in coniferous forests, undergrowth, and clearings in North America. Wintergreen was known by the North American Indians who used its leaves in traditional medicine to treat various ailments (headaches, backaches, fever, etc.). Wintergreen leaves were also used by the Amerindians for medicinal purposes. Wintergreen decoctions were gargled to soothe sore throats or applied in dressings to treat skin inflammations. Chemical analysis of the active components established the presence of methyl salicylate. William Procter isolated this component of Wintergreen essential oil in1844 and Auguste Cahours hydrolysed it into salicylic acid, a precursor of aspirin. Wintergreen is known by this name in North America because of the persistence of the leaves in winter. It is also known as Canada Tea or Mountain Tea because its leaves are often used to make Tea.