Ochrolechia tartarea Cudbear / Crottle

Thallus thick, with a grainy pale grey surface. The apothecia are conspicuous and often densely clustered, the disc is finely granular, pale brown/pinkish, with a thick margin thick. Spores 40-70 x 20-40 µm. Apothecia discs: C + red, K-, KC + red, P-: thallus: C + red-orange, K + pale yellow, KC + red; medulla: P-. An uncommon species in West Glamorgan, with records coming from quartz-conglomerate outcrops and boulders associated with the Brownstones Formation of western Gower and Carboniferous sandstone at Melincwrt.

Listed by Alan Orange in Flora of Glamorgan (Wade et al, 1994).