A lichen grown on oak trees. Its odor is earthy, woody and slightly leathery. It is used as a fixative in many blends, especially chypre.

Oakmoss, also known as Evernia prunastri, is a type of lichen used extensively in modern perfumery. This lichen can be found in many mountainous temperate forests throughout the Northern Hemisphere, including parts of France, Portugal, Spain, North America, and much of Central Europe. Oakmoss grows primarily on the trunk and branches of oak trees, but is also commonly found on the bark of other decideous trees and conifers such as fir and pine.