''Leucodermia'' is a

genus 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 nom ...

of lichen-forming

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

in the family

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 wi ...

Taxonomy

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 ...

by German lichenologist

Klaus Kalb Klaus Kalb (born 1942) is a German lichenologist and an authority on tropical lichens. Biography Klaus Kalb was born in Nuremberg in 1942 and grew up in southern Bavaria. From 1960 to 1965 he studied biology, chemistry, and geography at t ...

in 2015, with '' Leucodermia leucomelos'' assigned as 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 specime ...

. ''Leucodermia'' includes lichens that were previously classified in genus ''

Anaptychia ''Anaptychia'' is a genus of lichenized fungi in the family Physciaceae. Species , Species Fungorum ''Index Fungorum'' is an international project to index all formal names (scientific names) in the fungus kingdom. the project is based at ...

section Section, Sectioning or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sig ...

''Polyblastidium''

series Series may refer to: People with the name * Caroline Series (born 1951), English mathematician, daughter of George Series * George Series (1920–1995), English physicist Arts, entertainment, and media Music * Series, the ordered sets used in ...

''leucomelaenae''. The genus name combines ''leucomelaenae'' with ''Heterodermia''. Klaus included 10 species in his original circumscription of the genus; ''

Leucodermia guzmaniana ''Leucodermia'' is a genus of lichen-forming fungi in the family Physciaceae. Taxonomy The genus was circumscribed by German lichenologist Klaus Kalb in 2015, with '' Leucodermia leucomelos'' assigned as the type species. ''Leucodermia'' includ ...

'' was added as a newly described species in 2019.

Description

Characteristics of genus ''Leucodermia'' include a

thallus Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms ...

that is either

leafy LEAFY (abbreviated LFY) is a plant gene that causes groups of undifferentiated Cell (biology), cells called meristems to develop into flowers instead of leaves with associated shoots. ''LEAFY'' is involved in floral meristem identity. ''LEAFY'' ...

(''foliose'') to somewhat bushy (''subfruticose'') with lobes that are linear-elongate, ribbon-like, and dichotomously branched. The lobes have conspicuous, long

rhizine In lichens, rhizines are multicellular root-like structures, arising mostly from the lower surface. A lichen with rhizines is termed rhizinate, while a lichen lacking rhizines is termed erhizinate. Rhizines serve only to anchor the lichen to their ...

s at their margins. The thallus is loosely attached to the substrate and lacks a lower

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

. The apothecia often have

pruinose Pruinescence , or pruinosity, is a "frosted" or dusty-looking coating on top of a surface. It may also be called a pruina (plural: ''pruinae''), from the Latin word for hoarfrost. The adjectival form is pruinose . Entomology In insects, a "blo ...

discs and '' Polyblastidium''-type

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, with sporoblastidia (small chambers in a thick-walled spore).

Species

*'' Leucodermia appalachensis'' – United States *'' Leucodermia arsenei'' – Mexico *''

Leucodermia borphyllidiata ''Leucodermia'' is a genus of lichen-forming fungi in the family Physciaceae. Taxonomy The genus was circumscribed by German lichenologist Klaus Kalb in 2015, with '' Leucodermia leucomelos'' assigned as the type species. ''Leucodermia'' includ ...

'' – Thailand *'' Leucodermia boryi'' – widespread *'' Leucodermia ciliatomarginata'' *'' Leucodermia circinalis'' – South America *'' Leucodermia fertilis'' – South America *''

'' – Mexico *'' Leucodermia leucomelos'' – widespread *'' Leucodermia lutescens'' – Mexico; South America *''

Leucodermia vulgaris ''Leucodermia'' is a genus of lichen-forming fungi in the family Physciaceae. Taxonomy The genus was circumscription (taxonomy), circumscribed by German lichenologist Klaus Kalb in 2015, with ''Leucodermia leucomelos'' assigned as the type speci ...

'' – South America

References

{{Taxonbar, from=Q41438095 Caliciales Caliciales genera Lichen genera Taxa described in 2015 Taxa named by Klaus Kalb