''Atrophysma'' 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 ...

in the family

Pannariaceae The Pannariaceae are a family of lichens in the order Peltigerales (suborder Collematineae). Species from this family have a widespread distribution, but are especially prevalent in southern temperate regions. Genera According to a recent (202 ...

. It contains the single species ''Atrophysma cyanomelanos'', a

crustose lichen Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichen ...

found only in

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

Taxonomy

Both the genus and species were described as new to science in 2020 by lichenologist Toby Spribille. The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

was discovered in

Glacier Bay National Park Glacier Bay National Park and Preserve is an American national park located in Southeast Alaska west of Juneau. President Calvin Coolidge proclaimed the area around Glacier Bay a national monument under the Antiquities Act on February 26, 1925. C ...

, where it was found growing on

argillite :''"Argillite" may also refer to Argillite, Kentucky.'' Argillite () is a fine-grained sedimentary rock composed predominantly of indurated clay particles. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts ...

rock on the top of an alpine ridge; this location is typically covered by snow for most of the year. The generic name ''Atrophysma'' combines ''atra'' ("black") and ''physma'' ("to blow up or distend"); the

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

, which combines ''kyanos'' ("blue") and ''melas'' ("black"), alludes to the typical colors of the

thallus Thallus (plural: 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. Many of these organisms wer ...

and

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 ...

. The lichen had been discovered previously in a nearby location,

Klondike Gold Rush National Historical Park Klondike Gold Rush National Historical Park is a national historical park operated by the National Park Service that seeks to commemorate the Klondike Gold Rush of the late 1890s. Though the gold fields that were the ultimate goal of the stamped ...

, as part of a similar lichen research survey in that area. It had been tentatively assigned to the genus '' Santessoniella'', but not formally described as a new species. The material found at Glacier Bay National Park was more substantive, allowing for a fuller characterization of the species, as well as

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. This showed that the lichen belonged to a distinct

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, ...

among other members of the Pannariaceae, and so ''Atrophysma'' was proposed to contain it.

Description

''Atrophysma cyanomelanos'' is a

cyanolichen Cyanolichens are lichens that apart from the basic fungal component ("mycobiont"), contain cyanobacteria, otherwise known as blue-green algae, as the photosynthesizing component ("photobiont"). Overall, about a third of lichen photobionts are cyan ...

, meaning that it has

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 ...

(also known as blue-green algae) as a

photobiont A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.thallus Thallus (plural: 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. Many of these organisms wer ...

is an olivaceous-brown crust up to in diameter, although neighbouring thalli can coalesce to form larger entities. The thallus resembles a flattened coral with tiny finger-like lobes (measuring 70–150

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

in diameter) protruding through a black hypothallus. It has rounded, black

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 ...

(sexual reproductive organs), and simple

ascospore 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 ...

s that measure 11.0–16.0 by 7.1–8.1 μm.

References

{{Taxonbar, from=Q108628475 Lichen genera Monotypic Lecanoromycetes genera Peltigerales Peltigerales genera Taxa described in 2020 Taxa named by Toby Spribille Fungi without expected TNC conservation status