Granulating Rocktripe Lichen

Umbilicaria hirsuta is a species of rock-dwelling, foliose (leafy) lichen in the family Umbilicariaceae, known in North America as the granular rock tripe. The species was first published in 1793 by Johan Peter Westring, who credited Olof Swartz for the name and noted that the lichen could be used as a dye source. The species was later transferred to the genus Umbilicaria by Erik Acharius. In Europe it has been treated as part of a complex...