Lobothallia alphoplaca, the variable sunken disk lichen, is a creamy gray to brown,[1] placodioid areolate lichen that grows on rock in on rock and sometimes moss.[2] It prefers growing on siliceous rocks.[2] It is found in Europe, central Asia, and North America, where it grows in the southwestern deserts to central California.[2] The center has numerous crowded and deformed apothecia with rims of thallus-like tissue (lecanorine).[2] With dark reddish or grayish brown to black discs.[2] Lichen spot tests on the thallus and apothecia are C−, and KC−, with tests on the cortex K+ red, P+ orange, or K−, P− and on the medulla K+ red, and P+ orange.[2] It produces norstictic acid, constictic acid, or salazinic acid as secondary metabolites.[2]