''Stirtonia'' 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

Arthoniaceae The Arthoniaceae are a family (biology), family of lichenized, Lichenicolous fungus, lichenicolous and saprobic fungi in the order Arthoniales. The Arthoniaceae is the largest family of Arthoniales, with around 800 species. Most species in Arthon ...

. It contains 22 species of

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 ...

s found primarily in

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

regions.

Taxonomy

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 ...

by the British lichenologist Annie Lorrain Smith in 1926, with '' Stirtonia obvallata'' 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 ...

. The

species epithet Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In Taxonomy (biology), taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany) ...

honours the Scottish lichenologist James Stirton.

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 ...

of ''Stirtonia'' contains green algae as its partner. These algae belong to the genus '' Trentepohlia'' and are responsible for

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

within the lichen symbiosis. ''Stirtonia'' lichens reproduce sexually through spore-producing structures called asci. These asci are found in specialised areas of the thallus known as areas. A distinctive feature of ''Stirtonia'' is the presence of interascal

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 (fungal threads between the asci) that

anastomose An anastomosis (, : anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal (su ...

, or interconnect, forming a network. These hyphae are similar in appearance to the hyphae found in non-reproductive parts of the thallus and are not bound together by a jelly-like substance (hymenial gel) as seen in some other lichen genera. The of ''Stirtonia'' have a unique structure. They are divided only by transverse

septa SEPTA, the Southeastern Pennsylvania Transportation Authority, is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly four million people througho ...

(cross-walls), creating several segments along the length of the spore. The walls of these spores, including the septa, are thickened. This thickening results in the internal chambers () of the spores having a rounded or lens-like shape when viewed under a microscope.

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 ...

(in 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 22 species of ''Stirtonia''. * '' Stirtonia borinquensis'' * '' Stirtonia byssoidea'' –

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

* '' Stirtonia caribaea'' * '' Stirtonia coei'' – Florida * '' Stirtonia curvata'' * '' Stirtonia divaricatica'' – Florida * '' Stirtonia epiphylla'' –

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (; Seychellois Creole: ), is an island country and archipelagic state consisting of 155 islands (as per the Constitution) in the Indian Ocean. Its capital and largest city, Victoria, ...

* '' Stirtonia ghattensis'' – India * '' Stirtonia ibirapuitensis'' * '' Stirtonia isidiata'' * '' Stirtonia juaensis'' * '' Stirtonia latispora'' – Florida * '' Stirtonia lucida'' – Brazil * '' Stirtonia microspora'' * '' Stirtonia neotropica'' * '' Stirtonia nitida'' * '' Stirtonia nivea'' * '' Stirtonia obvallata'' * '' Stirtonia ochracea'' – Brazil * '' Stirtonia psoromica'' * '' Stirtonia punctiformis'' * '' Stirtonia rhizophorae'' * '' Stirtonia schummii'' * '' Stirtonia viridis''

References

{{Taxonbar, from=Q7617621 Arthoniaceae Lichen genera Arthoniomycetes genera Taxa described in 1926 Taxa named by Annie Lorrain Smith