Kuettlingeria

Kuettlingeria is a genus of saxicolous (rock-dwelling), crustose lichens in the family Teloschistaceae. Species are characterized by a white or gray thallus and the presence of anthraquinones in the apothecial disc and true exciple, with the exception of Kuettlingeria diphyodes, which entirely lacks anthraquinones. First described by Italian botanist Trevisan in 1857, the genus includes 15 recognized species, although it is believed to be more diverse with additional unnamed species. These lichens are predominantly found in the Northern Hemisphere, particularly in the Mediterranean region, and grow on limestone and base-rich siliceous outcrops in sunlit conditions....read more on Wikipedia.