Evernia spp.
Various species of Evernia, primarily E. prunastri( L.) Ach., and occasionally even some Pseudevernia spp., the oakmoss lichens, are used in potpourri. The thallus is pale greenish yellow above and white on the underside in the native state with dichotomously branched, flattened branches, up to 70 mm long x 2-4 mm wide.
These oak mosses are circumboreal and epiphytic on trees or prostrate on the ground.
Parmeliaceae