Stories We Like: A Guide to the Comma
(Evernia prunastri), species of fruticose (branched, bushy) lichen valued in perfumery for its heavy, oriental fragrance and as a fixative base. It grows in mountainous areas throughout much of the Northern Hemisphere. The pale greenish gray thallus, 3 to 8 cm (1.2 to 3 inches) long, is palmately branched, ending in pointed tips. The upper surface is green and warty with pale gray reproductive bodies (soredia). The undersurface is whitish with a faint netlike pattern. A less common species (E. furfuracea), having similar properties, is often included under the same common name, which is a translation of the French mousse de chene.