Lecanora gangaleoides

A species that favours coastal areas, where it can be locally abundant on siliceous rocks, most notably quartz-rich Old Red Sandstone outcrops and old walls made of the same material in western Gower. Less frequent on Pennant Sandstones further east. The thallus is variable but is frequently warted, green/brown grey, with blackish apothecia to a wide pale margin. Cutting through an apothecium shows the pale green interior and scratching the thallus reveals an orange pigment of the photobiont. Can be confused with Tephromela atra, which shows a dark purple interior to the apothecia.

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