Species: Phaeophyscia orbicularis
Photos: On rock and deciduous tree-trunk. Cork, SW Ireland.
Small pale grey to brownish-grey orbicular thallus which can become bright green when wet. Long, palmately-divided lobes with black undersides and dark, protruding rhizines. Dense creamy-greenish soralia, mottled bluish-black. Apothecia are infrequent.
Common on nutrient-rich bark, twigs and stone, also found on concrete and roads in urban areas.
Orange-yellow patches on cortex and soredia are K+/- purple
Similar: Hyperphyscia adglutinata. White under-surface, few whitish rhizines.
Above: Phaeophyscia orbicularis on rock, Ballingeary area, Co.Cork. January 2009
Above: Phaeophyscia orbicularis on tree trunk. Macroom, Co.Cork. February 2009