Vagrant lichen
A vagrant lichen is a lichen that is either not attached to a substrate, or can become unattached then blow around, yet continue to grow and flourish.[1] Some authors use the expression "erratic lichen" as synonymous with "vagrant lichen", and others only for those lichens that never attach (obligate erratic).[1] Vagrant lichens generally occur in open and windswept habitats, all over the world, in all kinds of temperature zones.[1] Habitats include saltbush (mallee) vegetation zones in Australia, steppes of Eurasia, Arctic tundra, and the North American prairie.[1] They range from the low elevations of the Namib Desert to the high altitude Andean páramo.[1] There are under 100 identified vagrant species, most commonly in the Aspicilia and Xanthoparmelia genera.[1]