''Gyrographa'' is a

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 ...

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

-forming

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

in the family

Roccellaceae The Roccellaceae are a family (biology), family of mostly lichen-forming fungi in the order Arthoniales, established by the French botanist François Fulgis Chevallier in 1826. Species in the family exhibit various lichen growth forms, growth ...

. The genus was

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

in 2014 by Damien Ernst and Anders Tehler, with ''Gyrographa gyrocarpa'' assigned as the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

. This lichen, originally described by Julius von Flotow in 1825, was first placed in the genus '' Opegrapha''. Species in the genus have a

crustose Crustose is a Habit (biology), habit of some types of algae and lichens in which the organism grows tightly appressed to a substrate, forming a biological layer. ''Crustose'' adheres very closely to the Substrate (biology), substrates at all poin ...

thallus lacking a

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 ...

, and a dark brown

prothallus A prothallus, or prothallium, (from Latin ''pro'' = forwards and Greek ''θαλλος'' (''thallos'') = twig) is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young ...

. The

photobiont A lichen ( , ) is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualistic relationship.

partner is trentepholioid. The is thick and carbonised, and the

ascospore In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...

s lack a gelatinous sheath; these characteristics distinguish it from '' Opegrapha'' species. The genus name alludes to the

ascomata An ascocarp, or ascoma (: ascomata), is the fruiting body (sporocarp (fungi), sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded ascus, asci, each of which typically contains four to ...

of the type species.

Taxonomy

''Gyrographa'' was erected in 2014 by Damien Ertz and Anders Tehler during a broad two- locus revision of the

that sought to bring the family's genera into line with

molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

phylogeny.

DNA sequence A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nu ...

s from the nuclear large-subunit ribosomal RNA and RPB2 genes showed that several erstwhile ''Opegrapha'' species actually form three separate lineages inside the Roccellaceae; to keep each lineage

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

the authors described the new genera ''Gyrographa'', '' Vigneronia'', and '' Pseudoschismatomma''. Within the

family tree A family tree, also called a genealogy or a pedigree chart, is a chart representing family relationships in a conventional tree structure. More detailed family trees, used in medicine and social work, are known as genograms. Representations of ...

''Gyrographa'' groups tightly with '' Psoronactis'' and is separated from other roccellacean clades by branches that enjoy maximal statistical support. This placement confirms that the genus belongs to the order

Arthoniales The Arthoniales is the second largest order of mainly crustose lichens, but fruticose lichens are present as well. The order contains around 1500 species, while the largest order with lichenized fungi, the Lecanorales, contains more than 14000 s ...

, class

Arthoniomycetes Arthoniomycetes are a class of ascomycete fungi. It includes two orders: Arthoniales and Lichenostigmatales. Most of the taxa in these orders are tropical and subtropical lichens. Systematics Phylogenetic analysis supports the monophyly of thi ...

, rather than the Opegraphaceae where its species had long been listed on morphological grounds. The circumscription initially encompassed two

saxicolous lichen A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, give ...

s: the

''G. gyrocarpa'' and ''G. saxigena''. They were transferred from ''Opegrapha'' because they combine three traits that are uncommon elsewhere in the Roccellaceae—black knot-like or short lirellate ascomata with a thick carbonised hypothecium, a persistent black margin, and colourless three-septate spores that lack the gelatinous envelope typical of most ''Opegrapha'' species. The generic name refers to the faintly wrinkled () outline of the fruit bodies in the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

collection. Subsequent collections and sequence data have upheld the genus as a coherent, well-supported lineage within the Roccellaceae, providing a clear framework for recognising any additional species that share its distinctive combination of DNA signature and morphological characters.

Description

The

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 ...

forms a crust that is tightly bonded to its

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (aquatic environment), the earthy material that exi ...

(crustose) and lacks a true protective skin (non-). It ranges in colour from grey-cream through dark or purplish brown and can appear faintly pink when freshly collected. Although it may reach up to 2 mm thick, it is usually much thinner. Powdery reproductive patches (

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 ...

) are sometimes present; these begin as discrete round spots 0.3–1.5 mm across but soon merge into broad dull yellow-grey to pinkish swathes, the pink tinge fading in the

herbarium A herbarium (plural: herbaria) is a collection of preserved plant biological specimen, specimens and associated data used for scientific study. The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sh ...

. A dark-brown fibrous often fringes the thallus, and the

photosynthetic Photosynthesis ( ) is a Biological system, system of biological processes by which Photoautotrophism, photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical ener ...

partner is a filamentous orange alga of the genus '' Trentepohlia''. The fruit bodies (ascomata) of ''Gyrographa'' are usually , appearing either knot-like clusters with a wrinkled () outline or short slit-shaped . They are black, never dusted with a pale bloom, and keep a conspicuous black margin even when the is narrowly exposed. The rim (excipulum) is dark brown and turns olive with potassium hydroxide (K+ olivaceous), while the tissue beneath the spore layer () is exceptionally thick and jet-black (). The spore-bearing layer (

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 ...

) yields a reddish

staining Staining is a technique used to enhance contrast in samples, generally at the Microscope, microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissue (biology), tissues), in cytology (microscopic ...

reaction with

iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

(I+ red). Inside, slender, branched filaments () weave between 8-spored, club-shaped asci. Spores are colourless, 3-septate, 15–25 × 4–6

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 ...

, straight, and lack the gelatinous envelope seen in many relatives. Minute flask-like

pycnidia A pycnidium (plural pycnidia) is an asexual fruiting body produced by mitosporic fungi, for instance in the order Sphaeropsidales ( Deuteromycota, Coelomycetes) or order Pleosporales (Ascomycota, Dothideomycetes). It is often spherical or inve ...

generate rod-shaped

conidia A conidium ( ; : conidia), sometimes termed an asexual chlamydospore or chlamydoconidium (: chlamydoconidia), is an asexual, non- motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also ...

measuring 4–7 × 0.3–0.8 μm. Standard spot tests show the thallus either unreactive (C–) or briefly red with bleach (C+), K–, and KC+ (red);

thin-layer chromatography Thin-layer chromatography (TLC) is a chromatography technique that separates components in non-volatile mixtures. It is performed on a TLC plate made up of a non-reactive solid coated with a thin layer of adsorbent material. This is called the sta ...

detects gyrophoric and/or schizopeltic acids, though some specimens contain no

secondary metabolite Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...

s. These combined traits—especially the carbonised hypothecium and unsheathed spores—separate ''Gyrographa'' from superficially similar former ''Opegrapha'' species.

Species

Species Fungorum ''Index Fungorum'' is an international project to index all formal names (Binomial nomenclature, scientific names) in the fungus Kingdom (biology), kingdom. As of 2015, the project is based at the Royal Botanic Gardens, Kew, one of three partn ...

(via the

Catalogue of Life The Catalogue of Life (CoL) is an online database that provides an index of known species of animals, plants, fungi, and microorganisms. It was created in 2001 as a partnership between the global Species 2000 and the American Integrated Taxono ...

) accepts four species of ''Gyrographa'': * '' Gyrographa fecunda'' – Australia * '' Gyrographa gyrocarpa'' * '' Gyrographa nigrofusca'' – India * '' Gyrographa saxigena''

References

{{Taxonbar, from=Q21230882 Roccellaceae Lichen genera Arthoniomycetes genera Taxa described in 2014 Taxa named by Damien Ertz Taxa named by Anders Tehler