''Leucodermia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

-forming

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

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. Description The Physiaceae family includes various ...

Taxonomy

The genus was

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

by German lichenologist

Klaus Kalb Klaus Kalb (born 1942) is a German lichenologist and an authority on tropical lichens. Born in Nuremberg, he studied at the University of Erlangen–Nuremberg before pursuing a career that significantly advanced the field of lichenology, parti ...

in 2015, with '' Leucodermia leucomelos'' assigned as the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

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

Anaptychia ''Anaptychia'' is a genus of lichen-forming fungi in the family Physciaceae. ''Anaptychia'' species are foliose (leafy) to fruticose (bushy) lichens. They have brown, thin-walled spores with a single septum, and a upper . Taxonomy The genus wa ...

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 i ...

''leucomelaenae''. The genus name combines ''leucomelaenae'' with ''Heterodermia''. Klaus included 10 species in his original circumscription of the genus; '' Leucodermia guzmaniana'' was added as a newly described species in 2019.

Description

Characteristics of genus ''Leucodermia'' include a

thallus Thallus (: 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. A thallus usually names the entir ...

that is either

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

(''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 mainly 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 ...

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 "bloom" ...

discs and '' Polyblastidium''-type

ascospore In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...

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

Species

*'' Leucodermia appalachensis'' – United States *'' Leucodermia arsenei'' – Mexico *'' Leucodermia borphyllidiata'' – Thailand *'' Leucodermia boryi'' – widespread *'' Leucodermia ciliatomarginata'' *'' Leucodermia circinalis'' – South America *'' Leucodermia fertilis'' – South America *'' Leucodermia guzmaniana'' – Mexico *'' Leucodermia leucomelos'' – widespread *'' Leucodermia lutescens'' – Mexico; South America *'' Leucodermia vulgaris'' – South America

References

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