Nephroma arcticum

Nephroma arcticum, the arctic kidney lichen, is a species of foliose (leafy), terricolous (ground-dwelling) lichen in the family Parmeliaceae. It has a yellowish-green thallus up to 8 cm (3 in) across made of large lobes, with a dark, tomentose lower surface. It is a tripartite lichen, consisting of a fungus and two photobiont partners: a species of nitrogen-fixing cyanobacteria (contained within dark, blistered cephalodia), and a species of green alga. First described by Carl Linnaeus in 1753, it is one of only two Nephroma species in North America that use green algae as their primary photobiont. Nephroma arcticum is widely distributed throughout the circumpolar regions of Asia, Europe, and North America, where it grows in semi-open coniferous forests and mountainous birch forests on shaded and moist ground, on moss carpets or on mossy rocks. The species is ecologically significant for its role in nitrogen fixation and as a food source for various animals including reindeer and mount......read more on Wikipedia.