A crustose species with a bluish to brown-grey thallus that is thick and warted, cracked or with areoles that have flat or slightly convex tops, sharp edges and a slightly rough surface. It is usually surrounded by a dirty grey thallus. The apothecia are immersed, but become somewhat sessile with age.
Cortex and medulla: K-
In Scotland, Aspicilia caesiocinerea is widespread on nutrient-rich rocks, especially by lakes, seashores and bird-perching stones. Also on walls and memorials. BLS distribution map
scottishlichens.co.uk 