Chrysothrix flavovirens

About

Chrysothrix flavovirens is a species of crustose and corticolous (bark-dwelling) lichen in the family Chrysotrichaceae. It has a pale greenish-yellow thallus that contains rhizocarpic acid. This lichen forms powdery, granular crusts that spread extensively over tree bark and rarely produces fruiting bodies, instead reproducing mainly through tiny dust-like particles (soredia). Originally described from Norway in 1994, it is now known to be widespread across Europe and has also been found in Japan and North America, where it fluoresces orange under ultraviolet light due to its distinctive chemical composition.

Summary from Wikipedia