Candelina submexicana

Candelina submexicana is a species of saxicolous (rock-dwelling) crustose lichen in the family Candelariaceae. This small lichen forms yellow patches that hug tightly to rock surfaces, with flattened lobes radiating outward from the center. It is closely related to Candelina mexicana but can be distinguished by its smaller size, more reddish-yellow color, and different internal structure. The species grows in sunny, dry locations across Mexico, the southwestern United States, and Peru, typically on exposed non-limestone rocks....read more on Wikipedia.