The
Gaultheria species share the common characteristic of producing oil of wintergreen. Wintergreen oil is a pale yellow or pinkish fluid liquid that is strongly minty aromatic described as "fresh, sweet, and characteristically wintergreen" (components:
methyl salicylate (about 98%),
α-pinene,
myrcene,
delta-3-carene,
limonene,
3,7-guaiadiene, and
delta-cadinene) that gives such plants a distinctive "medicinal" smell whenever bruised.
Salicylate sensitivity is a common adverse reaction to the methyl salicylate in oil of wintergreen; it can produce allergy-like symptoms or
asthma. Wintergreen essential oil is usually obtained by
steam distillation of the leaves of the plant following maceration in warm water. Methyl salicylate is not present in the plant until formed by enzymatic action from a
glycoside within the leaves as they are macerated in warm water. Oil of wintergreen is also manufactured from some species of
birch, but these
deciduous trees are not called wintergreens.
Spiraea plants also contain methyl salicylate in large amounts and are used similarly to wintergreen. Wintergreen has a strong "minty" odor and flavor; however, the
Gaultheria-genus plants are not true mints, which belong to the genus
Mentha. Wintergreen also is used in some perfumery applications and as a
flavoring agent for
toothpaste,
chewing gum,
soft drinks,
confectionery,
Listerine, and
mint flavorings. Wintergreen is used for rust removal and degreasing of machinery and is particularly effective for breaking through sea water corrosion. ==Toxicity of oil==