Vagrant lichen

[1] 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".

[2] 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.