Chrysothrix onokoensis

Chrysothrix onokoensis is a species of crustose lichen in the family Chrysotrichaceae. Originally described as an alga by Francis Wolle in 1877, it was recognized as a lichen by Asa Gray shortly after, but not formally reclassified until 2008. This distinctive bright yellow to yellow-green lichen forms loosely attached, irregularly spreading patches on rock surfaces, primarily shaded sandstone. It has a somewhat disjunct distribution in the eastern United States, with most collections coming from the Ozark–St. Francis National Forest in Arkansas, though its type locality is in Glen Onoko, Pennsylvania. The species lacks known reproductive structures and is characterized by its two-layered structure consisting of yellow granules above and rhizohyphae below....read more on Wikipedia.