Nephroma helveticum

Nephroma helveticum, the fringed kidney lichen, is a species of cyanolichen in the family Peltigeraceae. First described by Erik Acharius in 1810, it is part of a complex taxonomic group that includes N. tropicum. Modern molecular studies have shown that material previously identified as N. helveticum actually comprises two distinct species. The species occurs in moist, shady environments, particularly in old-growth forests. In North America, it is found at low elevations in riparian areas with coastal influence, while in Europe, where it is extremely rare, it occurs in montane-oceanic regions and shows a preference for basic rock substrates. In Nordic countries, it is known from approximately 20 localities across Finland, Norway and Sweden, where it is considered critically endangered....read more on Wikipedia.