Buellia dispersa

Also known as Dispersed Buellia Lichen

Dull white to beige or dark brown, this crustose lichen forms distinct, closely packed areolas on non-calcareous rock surfaces throughout arid western landscapes. It thrives on exposed basalt, granite, and gneiss, enduring intense solar radiation and severe thermal swings. As a common pioneer species across the Sonoran and Mojave deserts, it contributes to rock weathering and stabilizes barren surfaces.