''Lichinodium'' 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 ...

filamentous lichen Lichens are composite organisms made up of multiple species: a fungal partner, one or more photosynthetic partners, and sometimes a basidiomycete yeast. They are regularly grouped by their external appearance – a characteristic known as their ...

s. It is the only genus in the family Lichinodiaceae, itself the only member of the order Lichinodiales. ''Lichinodium'' has four species. Previously considered part of the class

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 in 1 ...

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 revealed that ''Lichinodium'' represents a unique

lineage Lineage may refer to: Science * Lineage (anthropology), a group that can demonstrate its common descent from an apical ancestor or a direct line of descent from an ancestor * Lineage (evolution), a temporal sequence of individuals, populati ...

in the

Leotiomycetes The Leotiomycetes are a class of ascomycete fungi. Many of them cause serious plant diseases. Systematics The class Leotiomycetes contains numerous species with an anamorph placed within the ''fungi imperfecti'' (deuteromycota), that have only ...

—the first known group of lichen-forming fungi in this class.

Taxonomy

The genus ''Lichinodium'' is

typified Typification is a process of creating standard (''typical'') social construction based on standard assumptions. Discrimination based on typification is called typism. See also *Ideal type *Normal type *Typology Typology is the study of types or ...

by ''Lichinodium sirosiphoideum'', first described in 1875 by

William Nylander William Andrew Michael Junior Nylander Altelius (born 1 May 1996) is a Canadian-born Swedish professional ice hockey right winger for the Toronto Maple Leafs of the National Hockey League (NHL). Nylander was selected by the Maple Leafs in the ...

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 ...

added three species to the genus about a century later. ''Lichinodium'' used to be classified in the

, but

analysis published in 2018 showed that the genus was incorrectly classified there, and that instead it represents a new lichen-forming

in the superclass Sordariomyceta (containing the (

Laboulbeniomycetes The Laboulbeniomycetes are a unique group of fungi that are obligatorily associated with arthropods, either as external parasites ( Herpomycetales and Laboulbeniales) or for dispersal ( Pyxidiophorales). Herpomycetales and Laboulbeniales fun ...

, and the

Sordariomycetes Sordariomycetes is a class of fungi in the subdivision Pezizomycotina (Ascomycota), consisting of 28 orders, 90 families, 1344 genera. Sordariomycetes is from the Latin sordes (filth) because some species grow in animal feces, though growth habit ...

), a major fungal group that was not previously known to have any lichenised species. ''Lichinodium'' has a

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

relationship with the family

Leotiaceae The Leotiaceae are a family of fungi in the order Leotiales. Species in this family are saprobic, and have a wide distribution, especially in temperate regions. The family contains 7 genera and 34 species In biology, a species is the basic u ...

, and thus the order Lichinodiales is placed in the class

. Studies using

transmission electron microscopy Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a g ...

also showed that in ''Lichinodium'', there are no

haustoria In botany and mycology, a haustorium (plural haustoria) is a rootlike structure that grows into or around another structure to absorb water or nutrients. For example, in mistletoe or members of the broomrape family, the structure penetrates t ...

(microscopic root-like structures) made in the interface between mycobiont and cyanobiont; this difference further distinguishes ''Lichinodium'' from the Lichinomycetes.

Description

''Lichinodium'' lichens form tiny pads of branched filaments comprising threads of

cyanobiont Cyanobionts are cyanobacteria that live in symbiosis with a wide range of organisms such as terrestrial or aquatic plants; as well as, algal and fungal species. They can reside within extracellular or intracellular structures of the host. In order ...

s surrounded by

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

l cells forming a collar. The

apothecia 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 ...

are brownish and gelatinous, with an indistinct proper and thalline margin. Two species are known to produce asexual

conidiomata Conidiomata (singular: Conidioma) are blister-like fruiting structures produced by a specific type of fungus called a coelomycete. They are formed as a means of dispersing asexual spores call conidia, which they accomplish by creating the blister-li ...

. The

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

cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

in family

Nostocaceae The Nostocaceae are a family of cyanobacteria that forms filament-shaped colonies enclosed in mucus or a gelatinous sheath. Some genera in this family are found primarily in fresh water (such as ''Nostoc''), while others are found primarily in ...

. ''Lichinodium'' species generally prefer cool, humid environments, where they grow on

conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...

twigs, tree trunks, or rocks, sometimes along with or overgrowing other mosses and lichens.

Species

*'' Lichinodium ahlneri'' *'' Lichinodium canadense'' *''

Lichinodium saxicola ''Lichinodium'' is a genus of filamentous lichens. It is the only genus in the family Lichinodiaceae, itself the only member of the order Lichinodiales. ''Lichinodium'' has four species. Previously considered part of the class Lichinomycetes, mol ...

'' *''

Lichinodium sirosiphoideum ''Lichinodium'' is a genus of filamentous lichens. It is the only genus in the family Lichinodiaceae, itself the only member of the order Lichinodiales. ''Lichinodium'' has four species. Previously considered part of the class Lichinomycetes, mol ...

References

{{Taxonbar, from=Q6543297 Leotiomycetes Lichen genera Taxa described in 1875 Taxa named by William Nylander (botanist) Leotiomycetes genera