''Xylographaceae'' is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.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 order

Baeomycetales The Baeomycetales are an order of mostly lichen-forming fungi in the subclass Ostropomycetidae, in the class Lecanoromycetes. It contains 8 families, 33 genera and about 170 species. As a result of molecular phylogenetics research published in t ...

. It contains four

genera 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 nomenclat ...

and 25 species.

Taxonomy

The family 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 1888 by American lichenologist

Edward Tuckerman Edward Tuckerman (December 7, 1817 in Boston, Massachusetts – March 15, 1886) was an American botanist and professor who made significant contributions to the study of lichens and other alpine plants. He was a founding member of the Natura ...

(as "Xylographei"). His concept of the family included only ''

Agyrium ''Agyrium'' is a genus of saprophytic fungi in the family Agyriaceae. It probably evolved from a lichen ancestor, as it is closely related to many lichenized species of fungi. Taxonomy ''Agyrium'' was first proposed by Elias Magnus Fries in hi ...

'', and the

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...

, '' Xylographa''. In 1929, British lichenologist Walter Watson published a system of lichen classification and included the genera '' Lithographa'', '' Ptychographa'', and '' Encephalographa'' in the Xylographaceae, leaving out ''Agyrium''. After that, the family was rarely used until it was resurrected in 2015 following

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 of trapelioid fungi in the subclass Ostropomycetidae. In this analysis, it was determined that trapelioid

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

fall into two major

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

groups; the first group – containing the genera ''

Rimularia ''Rimularia'' is a genus of lichenized fungi in the family Trapeliaceae. ''Rimularia'' was circumscribed by Finnish botanist William Nylander William Andrew Michael Junior Nylander Altelius (born 1 May 1996) is a Canadian-born Swedish pr ...

'', ''

Placynthiella ''Placynthiella'' is a genus of lichenized fungi in the family Trapeliaceae. The genus was circumscribed by Russian lichenologist Alexander Elenkin in 1909, with '' Placynthiella arenicola'' designated as the type species In zoological nomenc ...

'', ''

Trapeliopsis ''Trapeliopsis'' is a genus of lichenized fungi in the family Trapeliaceae. It contains 20 species. The genus was circumscribed in 1980 by Hannes Hertel and Gotthard Schneider, with '' Trapeliopsis wallrothii'' designated as the type species I ...

'', ''

Trapelia ''Trapelia'' is a genus of lichenized fungi in the family Trapeliaceae Trapeliaceae is a family of lichens in the order Baeomycetales. The family contains 12 genera and about 125 species. Taxonomy Trapeliaceae was originally circumscribed ...

'', and ''

Placopsis ''Placopsis'' (bullseye lichen) is a genus of lichenized fungi in the family Trapeliaceae. Species , Species Fungorum (via the Catalog of Life) accepts 29 species of ''Placopsis''. *'' Placopsis ampliata'' *'' Placopsis antarctica'' *'' Pla ...

'' – are part of the family

Trapeliaceae Trapeliaceae is a family of lichens in the order Baeomycetales. The family contains 12 genera and about 125 species. Taxonomy Trapeliaceae was originally circumscribed by French lichenologist Maurice Choisy in 1929. Hannes Hertel emended the f ...

. The remaining trapelioid genera are in the Xylographaceae.

Description

Most species in the Xylographaceae have linearized, hysteriothecial

ascomata An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are mo ...

. These are ascomata with elongated ascocarps that are initially closed but open by means of a longitudinal fissure that exposes the

hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some ...

Genera

*'' Lambiella'' – 12 spp. *'' Lithographa'' – 10 spp. *'' Ptychographa'' – 1 sp. *'' Xylographa'' – 2 spp.

References

{{Taxonbar, from=Q28872310 Baeomycetales Lecanoromycetes families Taxa named by Edward Tuckerman Taxa described in 1888 Lichen families