A crustose species with a matt, yellow-brown to dark reddish brown, thick thallus that is divided into angular squamules or areoles that often have raised edges. The darker reddish-brown apothecia are immersed in these areoles.
Thallus: C+ red, K-
Though widespread in Scotland, Acarospora fuscata is less frequent in parts of the Highlands and south of the Central Belt. It is commonly found on nutrient-rich and -enriched, hard, siliceous rock, including bird perches and gravestones. BLS distribution map
Acarospora fuscata is distinguished from Acarospora smaragdula on basis of the areoles having raised edges and forming a continuous crust.
scottishlichens.co.uk 