Aspicilia cuprea, the copper sunken disk lichen, is a large 1ā diameter copperish-tan to brown crustose areolate lichen that forms large patches of adjacent lichens on rock (saxicolous).[1] It grows only from northern California to Baja California.[2] [1] It is common and characteristic of siliceous rock in interior valley and western mountains of California.[1] One to many irregularly shaped black apothecia are sunken into the thallus.[1] Lichen spot tests are K+ red, Cā, P+ orange, and Iā.[1]