Evernia

Evernia is a genus of lichenized fungi in the family Parmeliaceae. Members are foliose lichens that form flattened, leafy thalli, typically olive-green to gray-green, with irregular lobes and a wrinkled upper surface. The thalli are usually attached to the bark of deciduous trees but may occur on rocks in shaded, humid environments. They occur in temperate regions of Europe, North America, and Asia, often in old-growth or undisturbed forests. Like other lichens, Evernia results from a symbiosis between a fungal partner and a photosynthetic partner, usually a green alga, and obtains nutrients from rain and dust.

Two species are of particular economic and historical importance: Evernia prunastri and Evernia furfuracea. Evernia prunastri, commonly known as oak moss, has been widely used in the perfume industry as a source of oakmoss, contributing to fragrance bases and fixatives. Evernia furfuracea, another oakmoss-related species, has also been used in perfumery as an alternative source. In modern cosmetics and fragrances, oakmoss and its extracts are subject to regulatory controls because of allergenic compounds, and products often require labeling or substitutions.

Conservation concerns include overharvesting and habitat loss, which can reduce local populations. Lichens in general are sensitive to air pollution and habitat disturbance, which can affect their distribution and abundance, and Evernia is particularly affected by such stressors in heavily industrialized or polluted regions.

Taxonomy: Genus Evernia; family Parmeliaceae; order Lecanorales; class Lecanoromycetes; division Ascomycota; kingdom Fungi.