Buellia_spuria
Buellia spuria
Species of lichen in the family Caliciaceae
Buellia spuria, the disc lichen, is a white to light ashy gray crustose areolate lichen that grows on rocks (epilithic) in montane habitats.[2] It has a black edge from the conspicuous, more or less continuous prothallus, which can also be seen in the cracks between the areolas forming a hypothallus, and in sharp contrast with the whitish or ashy colored areolas.[2] It prefers mafic (siliceous) rock substrates.[2] In Joshua Tree National Park is can be seen on vertical granite and gneiss faces in washes.[3] It is common worldwide in the Northern Hemisphere.[2] It is very common in the Sonoran Desert from southern California to Arizona, Baja California, and Sonora, Chihuahua, and Sinaloa, Mexico.[2]
It is similar in appearance to Buellia stellulata, but has a different secondary chemistry, and B. spuria is common throughout the Sonoran Desert region, while B. stellulata is restricted to coastal regions.[2]
