Xanthoparmelia plittii (Gyel.) Hale
Parmelia plittii Gyel.
Plitt’s Rock Shield
This lichen is a North American native. It is also found in South America and South Africa.
Identification: This lichen is 1½-4" (4-10 cm) in diameter, found on exposed or partially shaded rock. It is foliose (leaflike). Tiny, fragile reproductive structures called isidia emerge from the surface. Except for the isidia, this lichen is identical to Xanthoparmelia cumberlandia
Xanthoparmelia plittii on Stephen Sharnoff Photography (excellent photos)
Xanthoparmelia plittii on Wikimedia Commons
Xanthoparmelia plittii description by Thomas H. Kent, last updated 12 Oct 2018.