# Porina

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Porina
> Markdown URL: https://mediated.wiki/source/Porina.md
> Source: https://en.wikipedia.org/wiki/Porina
> Source revision: 1291197772
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Genus of fungi

This article is about the genus of lichen-forming fungi. For the [bryozoan](/source/Bryozoa) genus, see [Porina (bryozoan)](/source/Porina_(bryozoan)).

Porina Porina exocha Scientific classification Kingdom: Fungi Division: Ascomycota Class: Lecanoromycetes Order: Gyalectales Family: Porinaceae Genus: Porina Ach. (1809) Type species Porina nucula Ach. (1809) Species 161

***Porina*** is a [genus](/source/Genus) of [crustose lichens](/source/Crustose_lichen) in the family [Porinaceae](/source/Porinaceae). As of August 2024[\[update\]](https://en.wikipedia.org/w/index.php?title=Porina&action=edit), [Species Fungorum](/source/Species_Fungorum) (in the [Catalogue of Life](/source/Catalogue_of_Life)) accepts 161 species of *Porina*.[1]

## Taxonomy

The genus was [circumscribed](/source/Circumscription_(taxonomy)) in 1809 by the Swedish lichenologist [Erik Acharius](/source/Erik_Acharius). His [diagnosis](/source/Glossary_of_lichen_terms#diagnosis) of the genus was as follows (translated from [Latin](/source/Latin)): "Apothecium wart-like, formed from the thallus, including several thalamia covered by a very delicate, transparent perithecium, marked above by impressed ostioles; nuclei somewhat globose, containing cellular vesicles. Thallus cartilaginous-membranous, uniform". Acharius included a single species in the genus, *Porina pertusa* (originally named by [Carl Linnaeus](/source/Carl_Linnaeus) in 1767 as *Lichen pertusus*);[2] this species is now known as *[Pertusaria pertusa](/source/Pertusaria_pertusa)*.[3]

## Description

The genus *Porina* comprises [crustose lichens](/source/Crustose_lichen), characterised by their crust-like appearance that can range from being completely immersed in their [substrate](/source/Glossary_of_lichen_terms#substrate) to sitting on the surface. The [thallus](/source/Thallus), or body of the lichen, may or may not have a protective outer layer called the [cortex](/source/Glossary_of_lichen_terms#cortex). Sometimes, an additional layer of dead cells known as the [epinecral layer](/source/Glossary_of_lichen_terms#epinecral_layer) is present. The internal structure, or [medulla](/source/Medulla_(lichenology)), is often not well-defined. Some species within this genus may develop [isidia](/source/Isidia)—small outgrowths that aid in [vegetative reproduction](/source/Vegetative_reproduction)—or, more rarely, [soralia](/source/Soralia), which are structures that produce [soredia](/source/Glossary_of_lichen_terms#soredia) for reproduction. The [photosynthetic](/source/Photosynthesis) partner, or [photobiont](/source/Glossary_of_lichen_terms#photobiont), in *Porina* is typically [green alga](/source/Green_alga) from the genus *[Trentepohlia](/source/Trentepohlia_(alga))*. However, in species that grow on leaves ([foliicolous](/source/Foliicolous_lichen) species), the photobiont can be *[Phycopeltis](/source/Phycopeltis)*.[4]

*Porina* lichens produce [perithecioid](/source/Glossary_of_lichen_terms#perithecioid) ascomata, which are flask-shaped structures where spores develop. These can be either embedded in the thallus, prominently protruding, or forming pits in limestone. The [exciple](/source/Glossary_of_lichen_terms#exciple), which is the outer layer of the ascomata, may contain dark pigments. Additionally, an [involucrellum](/source/Glossary_of_lichen_terms#involucrellum)—a layer of thick-walled cells—may be present, sometimes containing photobiont cells or crystals.[4]

The internal structure of the ascomata, or [hamathecium](/source/Glossary_of_lichen_terms#hamathecium), is made up of [paraphyses](/source/Paraphyses), which are generally unbranched filaments, and may or may not include [periphyses](/source/Glossary_of_lichen_terms#periphyses) (small filaments within the ascomata). The gel within the [hymenium](/source/Hymenium) (the fertile inner layer) does not react with [iodine](/source/Iodine) (I–) or [potassium iodide](/source/Potassium_iodide) (K/I–).[4]

The [asci](/source/Ascus), which are the spore-producing cells, are [clavate](/source/Glossary_of_lichen_terms#clavate)-cylindrical (club-shaped to cylindrical) and thin-walled. They are functionally [unitunicate](/source/Glossary_of_lichen_terms#unitunicate), meaning they open by splitting at the apex without any extruded layers. Depending on the species, the apex of the ascus may be truncate and have a refractive ring that stains with [Congo red](/source/Congo_red), or it can be rounded and lack this ring.[4]

[Ascospores](/source/Ascospore) in *Porina* are typically colourless and can have three to many transverse [septa](/source/Septum) (divisions), occasionally also having one to three longitudinal septa. They are usually narrowly [ellipsoidal](/source/Ellipsoid) to needle-like ([acicular](/source/Glossary_of_lichen_terms#acicular)) and smooth, often enclosed in a [perispore](/source/Glossary_of_lichen_terms#perispore). The arrangement of spores within the ascus is generally irregularly [biseriate](/source/Glossary_of_lichen_terms#biseriate) (arranged in two rows). *Porina* also produces [pycnidia](/source/Pycnidia), which are asexual reproductive structures. The [conidia](/source/Conidia) (asexual spores) are usually aseptate (without internal partitions), ranging from cylindric-ellipsoidal to rod-shaped or, more rarely, [filiform](/source/Glossary_of_lichen_terms#filiform) (thread-like).[4]

Chemically, *Porina* species lack [acetone](/source/Acetone)-soluble [secondary metabolites](/source/Secondary_metabolite) but contain at least four acetone-insoluble pigments. Among these, a yellow to orange pigment, reacting K+ (orange or dark orange) and [hydrochloric acid](/source/Hydrochloric_acid) (HCl+ yellow to orange), is known as *Porina*-yellow. This pigment is prevalent in various species such as *[P. ahlesiana](https://en.wikipedia.org/w/index.php?title=Porina_ahlesiana&action=edit&redlink=1)*, *[P. lectissima](https://en.wikipedia.org/w/index.php?title=Porina_lectissima&action=edit&redlink=1)*, and *[P. leptalea](https://en.wikipedia.org/w/index.php?title=Porina_leptalea&action=edit&redlink=1)*. Additionally, *Porina* lichens have various dark pigments that are often mixed and challenging to differentiate, with one distinctive pigment being purple-violet, reacting K+ (dark bluish-grey) and hydrochloric acid (HCl+ purple to red-purple).[4]

## References

1. **[^](#cite_ref-CoL_1-0)** ["*Porina*"](https://www.catalogueoflife.org/data/taxon/7PVG8). *[Catalogue of Life](/source/Catalogue_of_Life)*. [Species 2000](/source/Species_2000): Leiden, the Netherlands. Retrieved 4 August 2024.

1. **[^](#cite_ref-Acharius_1809_2-0)** Acharius, E. (1809). ["Förteckning pa de i Sverige växande arter af Lafvarnes famille"](https://www.biodiversitylibrary.org/page/46996843). *Kongliga Vetenskaps Academiens Nya Handlingar*. 2 (in Latin). **30**: 145–169 [158].

1. **[^](#cite_ref-IF:_Porina_pertusa_3-0)** ["Record Details: *Porina pertusa* (L.) Ach., K. Vetensk-Acad. Nya Handl. 30(3): 159 (1809)"](https://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=402215). [Index Fungorum](/source/Index_Fungorum). Retrieved 4 August 2024.

1. ^ [***a***](#cite_ref-Orange_et_al._2021_4-0) [***b***](#cite_ref-Orange_et_al._2021_4-1) [***c***](#cite_ref-Orange_et_al._2021_4-2) [***d***](#cite_ref-Orange_et_al._2021_4-3) [***e***](#cite_ref-Orange_et_al._2021_4-4) [***f***](#cite_ref-Orange_et_al._2021_4-5) Orange, A.; Cannon, P.; Malíček, J.; Sanderson, N.; Coppins, B.; Simkin, J. (2021). [*Ostropales: Porinaceae, including the genus*Porina](https://britishlichensociety.org.uk/sites/default/files/Porinaceae_0.pdf) (PDF). Revisions of British and Irish Lichens. Vol. 4. pp. 2–3.

Taxon identifiers Porina Wikidata: Q4172524 Wikispecies: Porina AusLichen: 30019293 CoL: 7PVG8 EoL: 16391 EPPO: 1PRNIG FloraBase: 27531 GBIF: 7250835 iNaturalist: 175276 IndexFungorum: 4337 IRMNG: 1265257 MycoBank: 4337 NBN: NBNSYS0000136849 NCBI: 146305 NZOR: b712dde5-f1b4-4470-a597-6a837c629864 Open Tree of Life: 713943 Paleobiology Database: 26139 PLANTS: PORIN SpeciesFungorum: 4337

---
Adapted from the Wikipedia article [Porina](https://en.wikipedia.org/wiki/Porina) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Porina?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.