Lecidea tessellata

Lecidea tessellata is a species of saxicolous (rock-dwelling), crustose lichen in the family Lecideaceae. It was formally described as a species in 1819 by German botanist Heinrich Flörke. In northern North America, it is common and widely distributed, growing on non-calcareous rocks. It also occurs in Afghanistan, China, Nepal, Europe, and Russian Asia. In India, it has been recorded only from the alpine Western Himalayas at an altitude of 3,450 m (11,320 ft). Its southern distribution extends to James Ross Island, where it is locally common....read more on Wikipedia.