Saxiloba pruinosa

Saxiloba pruinosa is a saxicolous (rock-dwelling) crustose lichen in the family Porinaceae. It is a small lichen that forms white to gray patches with a distinctive frosted appearance on granite boulders in primary rainforest in central Brazil. The species is highly distinctive for its unusual labyrinth-like pattern of non-frosted lines running across the frosted thallus surface, a combination of features not previously documented in any other lichen genus. It was formally described in 2022 from sterile material collected in the Reserva Cristalino region of Mato Grosso and remains known only from Brazil.