Verseghya thysanophora

Verseghya thysanophora, commonly known as the mapledust lichen, is a species of mostly corticolous (bark-dwelling), leprose lichen in the family Pertusariaceae. This common species is widely distributed in the Northern Hemisphere. The thallus of the lichen is a thin patchy layer of granular soredia, pale green to yellowish green in colour. The main characteristics of the lichen include the presence of lichen products known as thysanophora unknowns, and the conspicuous white, fibrous prothallus that encircles the thallus....read more on Wikipedia.