Wintergreen is the common name for smooth, low-growing, woodland, herbaceous plants in genus Pyrola of the wintergreen family (Pyrolaceae). These plants were known to the Cree as "beaver's ears" because of their small, round, evergreen leaves. Nine of the 12 known species are native to Canada. The name also applies to the closely related genera: Chimaphila (pipsissewa), with 3 species in Canada; and Moneses (one-flowered wintergreen), with one species in Canada. Also widely known as wintergreen is genus Gaultheria of the related heath family (Ericaceae). Gaultheria contains about 100 species worldwide, mostly in the Andes, and 5 native to Canada. Of these, the name wintergreen is most frequently used for G. procumbens, which has persistent leaves and dainty pink or white, urn-shaped flowers, followed by scarlet, berrylike capsules. This plant's volatile oil contains methyl salicylate (oil of wintergreen), which is used in perfumery; it was once valued in the treatment of rheumatic disorders but is now largely replaced by safer, synthetic formulations.