Rhizocarpon geographicum, commonly known as yellow map or world map l ichen .   Rhizocarpon geographicum is a very distinctive and bro...

  Xanthoparmelia is a genus of fair (from white and pale grey-green, to brownish) foliose lichens that are loosely attached to a rock. Mo...

Xanthoria parietina.   Commonly seen and also commonly overlooked, lichens are inherently attractive, the more so the more you observe...