Buellia spuria, the disc lichen, is a white to light ashy gray crustose areolate lichen that grows on rocks (epilithic) in montane habitats. 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. It prefers mafic (siliceous) rock substrates. In Joshua Tree National Park is can be seen on vertical granite and gneiss faces in washes. It is common worldwide in the Northern Hemisphere. It is very common in the Sonoran Desert from southern California to Arizona, Baja California, and Sonora, Chihuahua, and Sinaloa, Mexico.
From Wikipedia, under CC BY-SA 4.0.
Is it poisonous?
We have no record of Sunken Button Lichen being toxic, poisonous or venomous. That is not proof that it is safe. Never eat, touch or handle a wild plant, mushroom or animal on the strength of an identification; ask someone qualified.
Easily confused with
- Lecidea tessellata
- Rehmia reducta
- Aspicilia cinerea
- Porpidia tuberculosa
- Buellia mamillana
- Tephromela atra
Classification
- Kingdom
- Fungi
- Phylum
- Ascomycota
- Class
- Lecanoromycetes
- Order
- Caliciales
- Family
- Caliciaceae
- Genus
- Buellia
- Species
- Buellia spuria
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