A crustose species with a grey to buff grey thallus with a white prothallus. It forms large patches that often have distinctive growth rings towards the margin. The crust may be thick and warted in the centre, but there are normally no soralia. It is usually abundantly fertile with large apothecia that have thick margins. The disc is pink, but this is often concealed by a thick white pruina.
Thallus: C+ yellow, K-, UV- or UV+ slightly blue. Disc: C+ red, K-, UV-
In Scotland, Ochrolechia parella is common, apart from the core upland areas. It prefers siliceous to slightly base-rich rocks, and is often found on coastal rocks and sandstone gravestones. BLS distribution map
scottishlichens.co.uk 