Astrothelium norisianum

Astrothelium norisianum is a species of crustose lichen-forming fungus in the family Trypetheliaceae. The lichen forms a pale olive-yellow crusty patch on tree bark with a coarsely bumpy, gall-like surface. Its reproductive structures are grouped together in irregular to elongated clusters that are typically covered by a whitish surface layer and fluoresce yellow under ultraviolet light. The species occurs in humid forests from Mexico through Central America to the Amazon basin and Peru....read more on Wikipedia.