Wintergreen was originally a term referring to a plant that continues photosynthesis (i.e., remains green) throughout the winter. The term evergreen is now more commonly used for this character.

Wintergreen is also the name given to a range of evergreen plants throughout the world which all share a common characteristic of producing oil of wintergreen, the chemical methyl salicylate, which gives plants a distinctive "medicinal" smell when bruised.

• Several genera of herbaceous plants in the family Pyrolaceae, notably Pyrola, Orthilia , Moneses and Chimaphila , show this character and are called wintergreens.
• Some species of the shrub genus Gaultheria in the closely related family Ericaceae also show this character and are called wintergreens in North America.
• Some species of the herbaceous genus Trientalis in the unrelated family Primulaceae are known as 'Chickweed Wintergreen'.

• Some species of birch also produce oil of wintergreen, but these deciduous trees are not called wintergreens.