Lichinales is the sole order of

ascomycete Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defi ...

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 class Lichinomycetes. It contains three

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

: Gloeoheppiaceae (3

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 ...

Lichinaceae The Lichinaceae are a family of ascomycete fungi. Most species are lichenized with cyanobacteria, and have a distribution largely in temperate regions. Taxonomy The family was circumscribed in 1854 by Finnish lichenologist William Nylander. H ...

(43 genera), and Peltulaceae (1 genus). Most species are

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Aino Henssen Aino Marjatta Henssen (12 April 1925, Elberfeld – 29 August 2011, Marburg), was a German lichenologist and systematist. Her father, Gottfried Henssen, was a folklorist and her mother was Finns, Finnish. Education and career Henssen began her stu ...

and Burkhard Büdel. The class Lichinomycetes was created by Valérie Reeb, François Lutzoni and Claude Roux in 2004. A study published in late 2022 suggests that six classes of fungi, Candelariomycetes,

Coniocybomycetes The Coniocybaceae are the sole family of lichen-forming fungi in the Coniocybales, which itself is the only order in the class Coniocybomycetes. The family was circumscribed by Heinrich Gottlieb Ludwig Reichenbach in 1837. Both the order and the ...

Geoglossomycetes Geoglossaceae is a family of fungi in the order Geoglossales, class Geoglossomycetes. These fungi are broadly known as earth tongues. The ascocarps of most species in the family Geoglossaceae are terrestrial and are generally small, dark in colo ...

Lichinomycetes Lichinales is the sole order of ascomycete fungi in the class Lichinomycetes. It contains three families: Gloeoheppiaceae (3 genera), Lichinaceae (43 genera), and Peltulaceae (1 genus). Most species are lichenized. Lichinales was proposed ...

, Sareomycetes, and Xylonomycetes, are all part of a

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, ...

that has a

sister A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to refer to ...

relationship with a clade containing

Lecanoromycetes Lecanoromycetes is the largest class of lichenized fungi. It belongs to the subphylum Pezizomycotina in the phylum Ascomycota. The asci (spore-bearing cells) of the Lecanoromycetes most often release spores by rostrate dehiscence. Genera of unc ...

and

Eurotiomycetes Eurotiomycetes is a large class of ascomycetes with cleistothecial ascocarps within the subphylum Pezizomycotina, currently containing around 3810 species according to the Catalogue of Life. It is the third largest lichen A lichen ( , ) is ...

. Lichinomycetes is the oldest name among these orders, and so the authors used this name for the group.

Phylogenomic Phylogenomics is the intersection of the fields of evolution and genomics. The term has been used in multiple ways to refer to analysis that involves genome data and evolutionary reconstructions. It is a group of techniques within the larger fields ...

analysis of a 481-

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...

set showed that as a group, the Lichinomycetes have relatively small genomes, and fewer metabolic gene clusters; one consequence of this is an inability to break down

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

and

pectin Pectin ( grc, πηκτικός ': "congealed" and "curdled") is a heteropolysaccharide, a structural acid contained in the primary lamella, in the middle lamella, and in the cell walls of terrestrial plants. The principal, chemical component of ...

. Because of this reduced metabolic capability, Lichinomycetes fungi may have adapted to partner symbiotically with other species to compensate for these losses.

References

Lichinomycetes Lichen orders Ascomycota orders Taxa named by Aino Henssen Taxa described in 1986 {{Ascomycetes-stub