''Clavascidium'' is a

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 ...

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Verrucariaceae The Verrucariaceae are a family of mostly lichenised fungi in the order Verrucariales. The lichen-forming species, which comprise the vast majority of the family, have a wide variety of thallus forms, and include crustose (crust-like), foliose ( ...

. 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 1996 by Austrian lichenologist Othmar Breuss. Because the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the genus, ''Clavascidium umbrinum'', has been shown using

molecular phylogenetics 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 ...

to belong to genus ''

Placidium ''Placidium'' is a genus of crustose lichen, crustose to squamulose lichen, squamulose to almost foliose lichen, foliose lichens. The genus is in the family Verrucariaceae. Most members grow on soil (are terricolous), but some grow on rock (saxi ...

'',

Cécile Gueidan Cécile Gueidan is a mycologist and lichenologist who applies morphological and molecular biological methods to the origin and taxonomy of fungi that live in lichen symbioses and within rocks. Early life and education Gueidan began working on ...

and colleagues proposed to unite ''Clavascidium'' with ''Placidium'' in a 2009 publication. Despite this, the genus has been retained in recent publications of fungal classification.

Species

*''

Clavascidium antillarum ''Clavascidium'' is a genus of lichens in the family Verrucariaceae. The genus was circumscription (taxonomy), circumscribed in 1996 by Austrian lichenologist Othmar Breuss. Because the type species of the genus, ''Clavascidium umbrinum'', has b ...

'' *''

Clavascidium imitans ''Clavascidium'' is a genus of lichens in the family Verrucariaceae. The genus was circumscribed in 1996 by Austrian lichenologist Othmar Breuss. Because the type species of the genus, ''Clavascidium umbrinum'', has been shown using molecular ph ...

'' *''

Clavascidium kisovense ''Clavascidium'' is a genus of lichens in the family Verrucariaceae. The genus was circumscribed in 1996 by Austrian lichenologist Othmar Breuss. Because the type species of the genus, ''Clavascidium umbrinum'', has been shown using molecular ph ...

'' *''

Clavascidium krylovianum ''Clavascidium'' is a genus of lichens in the family Verrucariaceae. The genus was circumscribed in 1996 by Austrian lichenologist Othmar Breuss. Because the type species of the genus, ''Clavascidium umbrinum'', has been shown using molecular ph ...

'' *''

Clavascidium lacinulatum ''Clavascidium lacinulatum'' is a dark brown squamulous terricolous lichen.Lichen Flora of the Greater Sonoran Desert Region. Vol 1, Nash, T.H., Ryan, B.D., Gries, C., Bugartz, F., (eds.), 2001/ref>Field Guide to California Lichens, Stephen Sha ...

'' *''

Clavascidium pseudorufescens ''Clavascidium'' is a genus of lichens in the family Verrucariaceae. The genus was circumscribed in 1996 by Austrian lichenologist Othmar Breuss. Because the type species of the genus, ''Clavascidium umbrinum'', has been shown using molecular ph ...

'' *''

Clavascidium semaforonense ''Clavascidium'' is a genus of lichens in the family Verrucariaceae. The genus was circumscribed in 1996 by Austrian lichenologist Othmar Breuss. Because the type species of the genus, ''Clavascidium umbrinum'', has been shown using molecular ph ...

'' *''

Clavascidium sinense ''Clavascidium sinense'' is a species of squamulose (scaley), ground-dwelling lichen in the family Verrucariaceae. Found in Northwest China, it was formally described as a new species in 2022 by Tingting Zhang and Xinli Wei. The type specimen w ...

'' – China A couple of species once proposed for inclusion in this genus are now classified in other genera: *''Clavascidium liratum'' is now ''

Anthracocarpon virescens ''Anthracocarpon'' is a genus of lichen-forming fungi in the family Verrucariaceae. The genus was circumscribed by Austrian lichenologist Othmar Breuss in 1996 with '' Anthracocarpon virescens'' assigned as the type species In zoological nomen ...

'' *''Clavascidium umbrinum'' is now ''

Placidium umbrinum ''Placidium'' is a genus of crustose to squamulose to almost foliose lichens. The genus is in the family Verrucariaceae. Most members grow on soil (are terricolous), but some grow on rock (saxicolous). The fruiting bodies are perithecia, flask-l ...

''. A proposed generic transfer of ''Catapyrenium alvarense'' to ''Clavascidium'' in 2017 was invalidly published according to nomenclatural rules.

References

Eurotiomycetes genera Lichen genera Verrucariales {{Eurotiomycetes-stub