Halecania

Halecania is a genus of fungi in the family Leprocaulaceae. It has 24 species. These lichens form inconspicuous, crust-like films that spread over rock or other surfaces, with colours ranging from chalky white through bluish-grey to brownish-grey and textures that can be cracked like dried mud, granular, or covered in tiny warts. They reproduce through small, disc-shaped fruiting bodies that contain eight colourless ascospores divided by a single cross-wall, with the spore envelope swelling conspicuously when treated with certain chemicals—a key identifying feature....read more on Wikipedia.