Synarthonia

Synarthonia is a genus of lichen-forming fungi in the order Arthoniales. The genus has not been placed into a family. These crustose lichens typically form thin, crust-like growths on tree bark in tropical and temperate regions worldwide, though many species have restricted geographical ranges and are known only from single locations. The genus is distinguished by its reproductive structures, which appear as small grouped patches on the lichen surface, and by its spores that change from colourless to brownish as they mature and have distinctive enlarged tip cells. While most species form traditional lichen partnerships with green algae, some members of Synarthonia have evolved to grow parasitically on other lichen species, particularly targeting members of the genera Graphis and lichens in the family Parmeliaceae....read more on Wikipedia.