Lecidea lithophila

A crustose lichen with a cracked-areolate thallus that is pale grey to grey-blue and usually stained rust-red in patches. The apothecia are large and usually become somewhat sessile. The discs are black, but become brown when wet.

Thallus: C-, K-, UV-

Lecidea lithophila occurs throughout most of Scotland where it is found on siliceous rocks that can be rich in iron. BLS distribution map