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 in the family Teloschistaceae. It contains seven species of corticolous (bark-dwelling), crustose lichens that occur in the Southern Hemisphere.
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 po ...
the genus ''Marchantiana'' in 2014, as part of a
taxonomic
Taxonomy is the practice and science of categorization or classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
revision of the subfamily Caloplacoideae of the family Teloschistaceae. They designated '' Marchantiana occidentalis'' as its type species. Initially, the genus comprised six species, all native to the Southern Hemisphere, with all but one species from Australia. The genus was named in honour of the Australian botanist Neville Graeme Marchant, to acknowledge his extensive contributions to the flora of Western Australia.
In their 2014 study, Kondratyuk and his team utilized
mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...
for
molecular analysis
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...
. Their findings suggested that while ''M. occidentalis'' holds a distinct position relative to other ''Marchantiana'' species, all species together form a well-supported monophyletic branch. Further, they suggested that ''Marchantiana'' occupied an "isolated position" in the subfamily Caloplacoideae. Further analysis in 2015 by Kondratyuk's team proposed ''Marchantiana'' to be
phylogenetically
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 ...
nested within the subfamily Brownlielloideae, and later in 2017, within the Teloschistoideae. However, a more recent 2021
molecular analysis
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...
focusing on specific, verified
genetic loci
In genetics, a locus (plural loci) is a specific, fixed position on a chromosome where a particular gene or genetic marker is located. Each chromosome carries many genes, with each gene occupying a different position or locus; in humans, the total ...
placed ''Marchantiana'' in the subfamily Caloplacoideae.
In 2023, an advanced molecular analysis using three genes revealed a close relation between ''Marchantiana'' and ''
Yoshimuria
''Yoshimuria'' is a genus of lichen-forming fungi in the family Teloschistaceae. It has four species of crustose lichens.
Taxonomy
The genus was circumscription (taxonomy), circumscribed in 2014 by a group of lichenologists, who assigned ''Yo ...
''. Sochting and colleagues noted that, while ''Marchantiana'' may seem
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
, its monophyletic origin is still plausible. They concluded that classifying ''Marchantiana'' as a monophyletic group was warranted, given the taxon's unique ecology and distribution. They subsequently added two newly described twig-growing lichen species from southern Patagonia, as well as three species transferred from other genera as new combinations.
Description
''Marchantiana'' has a crust-like thallus that can range in appearance from a continuous to a patchy texture. Its colour varies, encompassing pale grey, dark brownish-grey, dark greenish-grey, and even vibrant hues of yellow or orange. The layer is often thin and arranged in a specific cellular pattern known as . The can fall into three types: , , or . The of these structures are made of tissue. Each reproductive sac, or
ascus
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 ...
, contains eight spores that can are divided into 2, 3, or 4 compartments () by partitions called septa. Its
conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...
are rod-shaped or slightly elongated rod-shaped. Standard chemical spot tests indicate the thallus either remains unchanged (K−) or turns purple (K+) when exposed to a solution of potassium hydroxide, while the apothecia consistently turn purple. The secondary chemical composition of ''Marchantiana'' includes anthraquinones associated with parietin, fragilin, or neochloroemodin groups. Other compounds like dibenzofurans, related to the ascomatic acid , and lichexanthone are sometimes present. These secondary substances are predominantly found in the reproductive structures of the lichen.
Species
* ''
Marchantiana asserigena
''Marchantiana'' is a genus of lichen-forming fungi in the family Teloschistaceae. It contains seven species of corticolous lichen, corticolous (bark-dwelling), crustose lichens that occur in the Southern Hemisphere.
Taxonomy
Lichenologists Se ...
Marchantiana queenslandica
''Marchantiana'' is a genus of lichen-forming fungi in the family Teloschistaceae. It contains seven species of corticolous (bark-dwelling), crustose lichens that occur in the Southern Hemisphere.
Taxonomy
Lichenologists Sergey Kondratyuk, ...
''Marchantiana maulensis'' was later transferred to the genus ''
Villophora
''Villophora'' is a genus of lichen-forming fungi in the subfamily Teloschistoideae of the family Teloschistaceae. It has 9 species. The genus was circumscription (taxonomy), circumscribed in 2013 by Ulrik Søchting, Ulf Arup, and Patrik Frödén ...
'' as ''
Villophora maulensis
''Villophora'' is a genus of lichen-forming fungi in the subfamily Teloschistoideae of the family Teloschistaceae. It has 9 species. The genus was circumscribed in 2013 by Ulrik Søchting, Ulf Arup, and Patrik Frödén. They assigned ''Villopho ...