''Variospora flavescens'' is a species of saxicolous (rock-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 ...

in the family

Teloschistaceae The Teloschistaceae are a large family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. The family, estimated to contain over 1800 species, was extensively revised in 2013, including the creation o ...

. It is a common, widely distributed species and has been recorded in Africa, Asia, Europe, and Macaronesia.

Taxonomy

The species was first scientifically described by botanist William Hudson in 1762. He placed it in the eponymously named genus ''Lichen'', as was the standard practice in those times, following the example of

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

in his influential 1753 work ''

Species Plantarum ' (Latin for "The Species of Plants") is a book by Carl Linnaeus, originally published in 1753, which lists every species of plant known at the time, classified into genera. It is the first work to consistently apply binomial names and was the ...

''. In its long

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. ...

history, the species has acquired an extensive list of

synonyms A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

. For example, in early Italian literature, it was frequently referred to as ''Caloplaca murorum''.

Jack Laundon Jack Rodney Laundon (28 July 1934 – 31 December 2016) was a British lichenologist and became President of the British Lichen Society. Education and personal life Jack Rodney Laundon was born 28 July 1934 in Kettering, Northamptonshire. He was ...

placed the

taxon In biology, a taxon (back-formation from ''taxonomy''; plural 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 nam ...

in the genus ''

Caloplaca ''Caloplaca'' is a lichen genus comprising a number of distinct species. Members of the genus are commonly called firedot lichen, jewel lichen.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, gold lichens, "ora ...

'' in 1984, and it was known by this

binomial Binomial may refer to: In mathematics *Binomial (polynomial), a polynomial with two terms * Binomial coefficient, numbers appearing in the expansions of powers of binomials *Binomial QMF, a perfect-reconstruction orthogonal wavelet decomposition ...

until 2013, when Ulf Arup, Patrik Frödén, and Ulrik Søchting transferred it to the newly

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 polyg ...

genus '' Variospora''.

Description

''Variospora flavescens'' features a thallus, which forms large, evenly distributed, circular patches measuring or more in diameter. The 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 ...

are closely , with rounded or irregular shapes. Their surface has a matte texture, varying in colour from pale to deep orange. The lobe-ends of this lichen species are not widened but are rounded and convex. They can sometimes appear faintly , meaning they have a white, waxy, powdery coating. The lobes, which are pleated and sometimes overlapping, are situated close to each other. The centre of the thallus has a closely , uneven texture, composed of occasionally contorted and congested lobes. These central lobes are white and non-pigmented but are spotted with orange apothecia. These apothecia (cup-shaped fruiting bodies) reach up to 1.5 mm in diameter. They are primarily located at the centre of the thallus and are typically abundant and crowded. When young, they are flat but become convex as they age. The , or the border of the apothecia, is the same colour as the initially but becomes excluded over time. The disc varies in colour from orange to orange-brown. The

paraphyses Paraphyses are erect sterile filament-like support structures occurring among the reproductive apparatuses of fungi, ferns, bryophytes and some thallophytes. The singular form of the word is paraphysis. In certain fungi, they are part of the fe ...

(sterile fungal filaments) are slender and range from straight to , without noticeable swelling at the ends. The lemon-shaped measure 12–15 by 8–10

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 ...

, and are swollen at the

septum In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interatri ...

. The septum's breadth varies, reaching up to 5 μm wide.

Habitat and distribution

''Variospora flavescens'' is a saxicolous lichen that grows on

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adje ...

stone, including

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

, mortar, and

cement A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mix ...

. Rarely it has been found growing on bark, although those cases are typically limited to locations near dusty lime quarries. It is widely distributed, having been recorded in Africa, Asia, Europe, and Macaronesia. In the United Kingdom, although quite common, it is not found in air-polluted areas such as industrial regions in

Northern England Northern England, also known as the North of England, the North Country, or simply the North, is the northern area of England. It broadly corresponds to the former borders of Angle Northumbria, the Anglo-Scandinavian Kingdom of Jorvik, and the ...

, nor in the

Scottish Lowlands The Lowlands ( sco, Lallans or ; gd, a' Ghalldachd, , place of the foreigners, ) is a cultural and historical region of Scotland. Culturally, the Lowlands and the Highlands diverged from the Late Middle Ages into the modern period, when Lowl ...

References

{{Taxonbar, from=Q25386390 Teloschistales Lichen species Lichens described in 1762 Lichens of Africa Lichens of Asia Lichens of Europe Lichens of Macaronesia Taxa named by William Hudson (botanist)