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.[ Vagrant lichens, Australian Botanic Garden] Some authors reserve the expression " vagrant lichen" for those lichens that never attach, that is, those that are obligately vagrant, referring to vagrant forms of other species as "erratic lichen".[ Habitats include saltbush (mallee) vegetation zones in Australia, steppes of Eurasia, Arctic tundra, and the North American prairie.][ They range from the low elevations of the Namib Desert to the high-altitude Andean páramo.][ There are under 100 identified vagrant species, most commonly in the Aspicilia and Xanthoparmelia genera.][
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