Buellia frigida

About

Buellia frigida is a species of saxicolous (rock-dwelling), crustose lichen in the family Caliciaceae. It was first described from samples collected from the British National Antarctic Expedition of 1901–1904. It is endemic to maritime and continental Antarctica, where it is common and widespread, at altitudes up to about 2,000 m (6,600 ft). The characteristic appearance of this lichen features shades of grey and black divided into small polygonal patterns. The crusts can generally grow up to 7 cm in diameter, although neighbouring individuals may coalesce to form larger crusts. One of the defining characteristics of the lichen is a textured surface with deep cracks, creating the appearance of radiating lobes. These lobes, bordered by shallower fissures, give the lichen a distinctive appearance and textured surface.

Summary from Wikipedia