Acarospora fuscata ("brown cobblestone lichen") is a glossy pale or yellowish-brown areolate lichen with angular areolas that grows up to 10 cm (4 in) wide on non-calcareous rock in low and high elevations.:217 It grows in Europe and North America. It grows in southern California and on the eastern part of the Sierra Nevada range.:217 It may grow with the areolas disconnected.:217 The areolas may lift at the edges, but the areolas do not overlap like true squamules...
Baltzo, "Lichens of Mt. Diablo State Park", 1989.
-Collection at Mount Diablo summit, North side rock outcrops with Quercus, Pinus sabiniana.