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.
/ref> 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".Rosentreter, Roger, "Vagrant Lichens in North America," Bryologist 96(3) (1993) pg. 333. Online at https://www.jstor.org/stable/3243861?seq=1#page_scan_tab_contents Vagrant lichens generally occur in open and windswept habitats, all over the world, in all kinds of temperature zones. Habitats include saltbush (mallee) vegetation zones in Australia,

steppes In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, ...

of Eurasia,

Arctic tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless moun ...

, and the North American

prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...

. They range from the low elevations of the

Namib Desert The Namib ( ; pt, Namibe) is a coastal desert in Southern Africa. The name is of Khoekhoegowab origin and means "vast place". According to the broadest definition, the Namib stretches for more than along the Atlantic coasts of Angola, Namib ...

to the high altitude Andean

páramo Páramo () can refer to a variety of alpine tundra ecosystems located in the Andes Mountain Range, South America. Some ecologists describe the páramo broadly as "all high, tropical, montane vegetation above the continuous timberline". A narrower ...

. There are under 100 identified vagrant species, most commonly in the '' Aspicilia'' and '' Xanthoparmelia''

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

References

Lichenology {{lichen-stub