''Culbersonia'' is a fungal

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

in the family

Caliciaceae The Caliciaceae are a family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. Although the family has had its classification changed several times throughout its taxonomic history, the use of mode ...

. This is 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, containing the single

foliose lichen Foliose lichen is one of the morphological classes of lichens, which are complex organisms that arise from the symbiotic relationship between fungi and a photosynthetic partner, typically algae. This partnership allows lichen to live in diverse ...

''Culbersonia nubila'' (formerly called ''Culbersonia americana''). This species, which grows on trees and rocks, is found in dry

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

regions of the world, particularly in Africa and Central America.

Taxonomy

The genus ''Culbersonia'' 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 ...

by Theodore Esslinger in 2000, to contain a lichen he collected from

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

that he named ''Culbersonia americana''. The genus name of ''Culbersonia'' is in honour of Chicita Frances 'Nan' Culberson, (b.1931), an American botanist (Mycology und Lichenology), who worked as a botanical researcher at

Duke University Duke University is a private research university in Durham, North Carolina. Founded by Methodists and Quakers in the present-day city of Trinity in 1838, the school moved to Durham in 1892. In 1924, tobacco and electric power industrialist James ...

in Durham/North Carolina and William Louis "Bill" Culberson (1929–2003), an American lichenologist. As they were "longtime friends and mentors" of Esslinger. After ''Culbersonia americana'' was published, it was determined that the Arizona species was the same as one previously described from Africa in 1980 by Roland Moberg, called ''Pyxine nubila''. A

new combination ''Combinatio nova'', abbreviated ''comb. nov.'' (sometimes ''n. comb.''), is Latin for "new combination". It is used in taxonomic biology literature when a new name is introduced based on a pre-existing name. The term should not to be confused wi ...

was made in a 2002 publication, and the name ''Culbersonia nubila'' was proposed. ''Culbersonia'' was until recently thought to belong to the

Physciaceae The Physciaceae are a family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. A 2016 estimate placed 19 genera and 601 species in the family. Genera This is a list of the genera contained within ...

due to morphological similarities with some of the genera in that family. Recent (2019)

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

analysis showed that it forms a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

with ''

Pyxine ''Pyxine'' is a genus of foliose lichens in the family Caliciaceae. The genus has a widespread distribution in tropical regions. The presence or absence of the compound lichexanthone is a character Character or Characters may refer to: Arts ...

'' and ''

Diplotomma ''Diplotomma'' is a genus of lichenized fungi in the family Caliciaceae. The genus has a widespread distribution and contains about 29 species. The genus was circumscribed by Julius von Flotow in 1849. It was later wrapped into ''Buellia'' befo ...

'', both of which are in the Caliciaceae. These three genera are morphologically distinguished from the other Caliciaceae by the appressed

foliose Foliose lichen is one of the morphological classes of lichens, which are complex organisms that arise from the symbiotic relationship between fungi and a photosynthetic partner, typically algae. This partnership allows lichen to live in diverse ...

growth form and the absence of a mazaedium (a fruit body consisting of a powdery mass of free

ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...

s).

Habitat and distribution

''Culbersonia nubila'' grows on trees and rocks. It is found in dry

regions of the world, particularly in Africa and Central America.

References

{{Taxonbar, from=Q5192859, from2=Q10463446 Caliciales Lichen genera Caliciales genera Taxa described in 2000