Cladonia borealisCladonia borealis, commonly known as the boreal cup lichen, is a species of lichen in the genus Cladonia.DescriptionCladonia borealis is yellowish green to brown in color. It occurs in North and South America, Antarctica, Eurasia and many on islands. The ascoma, when present is apothecial.BiochemistryIts secondary metabolites include 4-O-demethylbarbatic acid, barbatic acid, rhodocladonic acid and usnic acid.