Astrothelium subendochryseum

Astrothelium subendochryseum is a species of crustose lichen-forming fungus in the family Trypetheliaceae. The lichen forms an olive-green crust on tree bark with a distinctively blistered to strongly uneven surface. Its reproductive structures are grouped together in irregular clusters that are partially covered by greenish tissue on the sides while exposing dark gray-brown tops with small black dots. The species occurs in Atlantic Forest regions of Brazil and has also been recorded from Central America, including El Salvador and Costa Rica....read more on Wikipedia.