Toninia squalida

Toninia squalida is a species of lichen in the family Ramalinaceae. It forms small brown scale-like structures that often merge into crusts, typically growing on calcareous rocks or base-rich soils in upland and arctic regions. The species was first described in 1810 by the Swedish lichenologist Erik Acharius as Lecidea squalida, and was transferred to the genus Toninia by Abramo Bartolommeo Massalongo in 1852. Found across the Northern Hemisphere from temperate mountains to arctic zones, it is a scarce alpine species in Britain, mainly recorded from the Scottish Highlands....read more on Wikipedia.