''Pyrenidium'' 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 ...

of lichenicolous (

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 ...

-dwelling)

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 ...

. It is the only genus in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Pyrenidiaceae. It has 13 species.

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 Finnish lichenologist

William Nylander William Andrew Michael Junior Nylander Altelius (born 1 May 1996) is a Swedish professional ice hockey Forward (ice hockey), forward for the Toronto Maple Leafs of the National Hockey League (NHL). Nylander was selected by the Maple Leafs in t ...

in 1865, with '' Pyrenidium actinellum'' 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 family was originally proposed by Alexander Zahlbruckner in 1898, and later resurrected for use in 2019. ''Pyrenidium'' was previously classified in Dacampiaceae, but

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 showed that this family was

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

, and that ''Pyrenidium'' originated from a lineage distinct from the genera in that family.

Description

Members of the genus have

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 ...

that are perithecioid in form, often with blue-green

pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...

in the upper wall of the peridia. Their ascomata are either immersed in the

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

thallus, or bursting through surface (), exposing the upper part of the structure (sometimes still covered by tissue of the host

thalli 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 ...

). They have asci that contain from four to eight

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. Infection by the fungus sometimes causes

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or war ...

-like malformations of the host thallus.

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 13 species of ''Pyrenidium'': * '' Pyrenidium actinellum'' * '' Pyrenidium aggregatum'' * '' Pyrenidium borbonicum'' * '' Pyrenidium coccineum'' * '' Pyrenidium cryptotheciae'' * '' Pyrenidium hetairizans'' * '' Pyrenidium hypotrachynae'' * '' Pyrenidium macrosporum'' * '' Pyrenidium octosporum'' * '' Pyrenidium santessonii'' * '' Pyrenidium sporopodiorum'' * '' Pyrenidium ucrainicum'' * '' Pyrenidium zamiae''

References

{{Taxonbar, from=Q10647248 Pleosporales Taxa described in 1865 Dothideomycetes genera Lichenicolous fungi Taxa named by William Nylander (botanist)