Rhizocarpon petraeum
Rhizocarpon petraeum is a species of lichen in the family Rhizocarpaceae. It contains stictic acid. It was first described as Lichen petraeus in 1787 by Franz Xaver von Wulfen, but was transferred to the genus Rhizocarpon in 1852 by Abramo Bartolommeo Massalongo. References Rhizocarpaceae Lichen species Lichens described in 1787 Taxa named by Franz Xaver von Wulfen