Tetramelas papillatus

Tetramelas papillatus is a species of crustose lichen in the family Caliciaceae. It was first described in 1826 by the Norwegian botanist Søren Christian Sommerfelt from specimens collected in northern Norway. The lichen forms a white, granular crust with small wart-like bumps and tiny black fruiting bodies. It grows primarily on rocks among mosses in regions with arctic and alpine climates, with a bipolar distribution spanning both polar regions and high mountains. The species has been transferred between several genera over nearly two centuries before being reclassified in Tetramelas in 2004....read more on Wikipedia.