Aspicilia phaea (dusky sunken disk lichen) is a grayish brown to tan areolate crustose lichen commonly found on rock in coastal to inland parts of central and southern California. Described as new to science in 2007, it is endemic to (only found in) California. It grows on exposed or partially shaded siliceous rock, with a few known occurrences on serpentine rock. The photobiont is a . In Joshua Tree National Park, it is commonly found to be infected with Lichenostigma, a genus or lichenicolous fungi (fungi that are parasitic on lichens).