DESCRIPTION: Foliose. The green-grey thallus is brown at the upturned edges when older and is wrinkled in appearance. Marginal soralia are common on the inner lobes and the surfaces of the entire fruiting body. By adding a droplet of bleach to a small section of the medulla and soredia a carmine-red reaction will take place. DISTRIBUTION: Widespread and common throughout. HABITAT: Found on the bark of a variety of trees.