Parmelia(redirected from Parmelia (disambiguation))
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a genus of lichens of the family Parmeliaceae. The foliaceous thallus has incised lobes and is whitish gray or yellowish green to dark brown. The lichen is loosely or closely attached to its substrate. There are approximately 700 species, distributed primarily in the tropics. Several species, including P. vagans and P. taractica, contain usnic acid, which has antibiotic properties. A number of species, such as P. saxatillis and P. conspersa, were formerly used as dyes.