Lichens are symbiotic organisms of fungi and algae. The biological significance of lichens and their metabolites has been reviewed by Huneck, who even stated that “good perfumes require lichen extracts.”1 Indeed, as of 1997, about 3,000 tons of lichen were processed—mainly in the Grasse, France area—for the manufacture of a wide variety of extracts, referred to as resinoids, and derived products (e.g. colorless/codistillation products, etc).
For a long time, there has been a misunderstanding on the true nature of the lichen extracts currently used in perfume compounding. Until recently, whatever the lichen species, such extracts were frequently called “oak moss”, concretes or resinoids. It is now well established that lichen growing on oak trees is specifically Evernia prunastri, whereas lichen growing on trees other than oak trees are called “tree moss”, which is predominantly Pseudevernia furfuracea (synonym: Parmelia furfuracea). Sometimes, the latter happens to be mixed with other minor species, such as Usnea.
Unfortunately, misidentification of the industrial extracts has not been totally eradicated. Indeed, while an RIFM monograph (#340) rightly mentions that oak moss resinoids are manufactured from Evernia prunastri, another one (#562) wrongly cites Usnea species as the sole raw material for manufacturing tree moss concretes.
