''Solitaria'' is a fungal

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

in the family

Teloschistaceae The Teloschistaceae are a large family (biology), family of mostly lichen-forming fungi belonging to the class (taxonomy), class Lecanoromycetes in the division (botany), division Ascomycota. The family has a cosmopolitan distribution, althoug ...

. It contains a single species, the

corticolous This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found ...

(bark-dwelling),

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 ...

''Solitaria chrysophthalma''.

Taxonomy

The species was first

formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

in 1944 by Swedish lichenologist

Gunnar Degelius Gunnar Bror Fritiof Degelius (né Nilsson until 1932; 27 January 1903 – 22 July 1993) was a Swedish lichenologist. Between the publications of his first and final scientific papers, Degelius had a 70-year-long research career. While he was b ...

, who named it ''Caloplaca chrysophthalma''. It had been known by several other names before this. Ulf Arup and colleagues transferred the

taxon In biology, a taxon (back-formation from ''taxonomy''; : 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 name and ...

to its own genus in 2013, following a

molecular phylogenetics 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 ...

-based restructuring of the family Teloschistaceae.

Description

''Solitaria chrysophthalma'' is characterised by a

thallus Thallus (: 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. A thallus usually names the entir ...

with a yellowish-green to grey hue, which extends between 90 and 100 mm. The vegetative tissue ranges from continuous to dispersed patterns, with initially appearing low and flat but occasionally slightly raised. Its

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

measures between 15 and 30 mm and houses a .

Soralia Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria or g ...

, specialised reproductive

propagule In biology, a propagule is any material that functions in propagating an organism to the next stage in its life cycle, such as by dispersal. The propagule is usually distinct in form from the parent organism. Propagules are produced by organisms ...

s, are well-defined, either round or irregular in shape, and contain finely textured with vibrant shades of yellowish-green to yellow-orange. Infrequently, the lichen bears

apothecia An ascocarp, or ascoma (: ascomata), 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. As ...

, flat reproductive structures where spores develop. These structures are coloured dark orange to bright orange, have a diameter of 0.3 to 0.7 mm, and may have a yellowish outer . 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 oth ...

, a fertile portion of the apothecia, varies in depth between 55 and 85

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

. It contains features like irregular

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 o ...

e or undefined oval cells. The asci, a compartment where spores mature, contains eight spores, each with two compartments (). The lichen displays a red reaction when treated with a solution of

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

, both on its thallus and .

Similar species

''Solitaria chrysophthalma'' and '' Lendemeriella lucifuga'' are lichen species that, while bearing some resemblances, exhibit distinct characteristics. ''Solitaria chrysophthalma'' is notable for its thicker, thallus with colours ranging from grey to various shades of yellow. This species occasionally presents an immersed thallus with scattered, light-yellow soralia. Furthermore, its soralia are bright orange-yellow, and it has bright orange apothecia, although not consistently. A key distinguishing feature is the absence of algal cell clusters in a cross-section of ''Solitaria chrysophthalma'', a feature present in ''Lendemeriella lucifuga''. In terms of chemical attributes, the former contains

parietin Parietin is the predominant cortical pigment of lichens in the genus '' Caloplaca'', a secondary product of the lichen '' Xanthoria parietina'', and a pigment found in the roots of curled dock (''Rumex crispus''). It has an orange-yellow color ...

as a dominant substance, supplemented by minor quantities of

emodin Emodin (6-methyl-1,3,8-trihydroxyanthraquinone) is an organic compound. Classified as an anthraquinone, it can be isolated from rhubarb, buckthorn, and Japanese knotweed ('' Reynoutria japonica'' syn. ''Polygonum cuspidatum''). Emodin is part ...

and

fragilin Fragilin is a chemical compound of the anthraquinone class. It has the molecular formula and is a chlorinated derivative of parietin. In 1965, it was reported as a constituent of the lichens ''Sphaerophorus fragilis'' and ''Sphaerophorus corall ...

, and lacks

fallacinal Fallacinal is an organic compound in the structural class of chemicals known as anthraquinones. It is found in many species of the lichen family Teloschistaceae. History In 1936, Japanese chemists Mitizo Asano and Sinobu Fuziwara reported on the ...

, which is found in the latter.

Habitat and distribution

''Solitaria chrysophthalma'' has been recorded in China and northern Europe. In North America, it occurs in central and eastern United States and Canada. It usually grows on bark, but, rarely, it is found on moss. Its range extends from southern

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

south to

Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...

and the mountains of northern

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

and

South Carolina South Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders North Carolina to the north and northeast, the Atlantic Ocean to the southeast, and Georgia (U.S. state), Georg ...

References

{{Taxonbar, from=Q27995972 Teloschistales Teloschistales genera Monotypic Lecanoromycetes genera Lichen genera Taxa described in 2013 Taxa named by Ulrik Søchting Taxa named by Patrik Frödén Taxa named by Ulf Arup