Lecanora confusa

Zeora confusa is a species of corticolous (bark-dwelling) crustose lichen in the family Lecanoraceae. It was described from Sweden in 1955 as Lecanora confusa. A later molecular study of Lecanora supported resurrecting the genus Zeora for the former Lecanora symmicta group, and the species was transferred accordingly. It grows on the bark of trees and shrubs, particularly in coastal areas of Europe and North America. First identified in Sweden in 1955, this small, greenish-grey lichen forms smooth patches and is recognized by its pale yellowish-green reproductive structures (apothecia). Once thought extinct in the Netherlands, it was rediscovered in 2000 growing primarily on poplar trees....read more on Wikipedia.