''Cetradonia'' is a

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Cladoniaceae The Cladoniaceae are a family of lichenized fungi in the order Lecanorales. It is one of the largest families of lichen-forming fungi, with about 560 species distributed amongst 17 genera. The reindeer moss and cup lichens (''Cladonia'') belong t ...

. A

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus, ''Cetradonia'' contains the single species ''Cetradonia linearis'' (formerly known as ''Cladonia linearis'' and as ''Gymnoderma lineare''). The genus was

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

in 2002 by Jiang-Chun Wei and

Teuvo Ahti Teuvo ("Ted") Tapio Ahti (born 1934) is a Finnish botanist and lichenologist. He has had a long career at the University of Helsinki that started in 1963, and then following his retirement in 1997, at the Botanical Museum of the Finnish Museum ...

. The genus was once placed in the family Cetradoniaceae (created in 2002) until that family was subsumed into the Cladoniaceae in 2006. ''Cetradonia linearis'', commonly known as the rock gnome lichen, is a

squamulose lichen A squamulose lichen is a lichen that is composed of small, often overlapping "scales" called squamules. If they are raised from the substrate and appear leafy, the lichen may appear to be a foliose lichen, but the underside does not have a "ski ...

found in the higher elevations of the southern

Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...

. Populations are only known to exist in

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

South Carolina )''Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...

and

Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...

. The lichen occurs only in frequent fog, or in deep river gorges. Because of its specialized habitat requirements and heavy collection for scientific purposes, the

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

since January 18, 1995. It is only one of two lichens on the endangered species list, the other being the Florida perforate cladonia.USFWS
Rock Gnome Lichen.
Asheville Field Office.

References

External links

Photograph of Rock gnome lichen
*USFWS
Rock Gnome Lichen Recovery Plan.
September 1997. Cladoniaceae Lichen genera Monotypic Lecanorales genera Fungi of the United States Taxa described in 2002 Taxa named by Teuvo Ahti {{Lecanorales-stub

See also

References

External links