Megaspora

Last updated

Megaspora
Megaspora verrucosa 97523.jpg
Close-up of thallus of Megaspora verrucosa with
half-hidden ( aspicilioid ) apothecia
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Pertusariales
Family: Megasporaceae
Genus: Megaspora
(Clauzade & Cl.Roux) Hafellner & V.Wirth (1987)
Type species
Megaspora verrucosa
(Ach.) Arcadia & A.Nordin (2012)
Species

M. cretacea
M. iranica
M. rimisorediata
M. verrucosa

Contents

Synonyms
  • Aspicilia subgen. MegasporaClauzade & Cl.Roux (1984) [1]

Megaspora is a genus of lichen-forming fungi in the family Megasporaceae. It contains four species of crustose lichens that typically grow on soil, bryophytes (mosses and liverworts), or plant litter on chalky substrates .

Taxonomy

The genus was circumscribed by Georges Clauzade and Claude Roux in 1984 with M. verrucosa assigned as the type species. [2]

In 2012, Linda in Arcadia and Anders Nordin proposed to conserve the name Megaspora verrucosa(Ach.) Arcadia & A.Nordin against M. verrucosaHafellner & V.Wirth due to taxonomic confusion stemming from historical errors in the original basionym citation. [3] The original introduction of Aspicilia subg. Megaspora erroneously cited Lecanora verrucosaAch. as the basionym, when it should have been Urceolaria verrucosaAch. This misattribution led to the invalid introduction of the name Megaspora verrucosa by Hafellner & Wirth based on the wrong species. To rectify this and prevent future taxonomic issues, the proposal suggested adopting M. verrucosa(Ach.) Arcadia & A.Nordin based on U. verrucosaAch. as the conserved name, which the Nomenclature Committee for Fungi eventually recommended accepting after initially considering rejection. [4]

Description

Megaspora is a genus of crustose lichens, meaning they form a crust-like growth on their substrate. The thallus (lichen body) is non- lobate (lacking distinct lobes) and can appear somewhat powdery ( pruinose ). The photobiont , or photosynthetic partner, in this lichen is chlorococcoid , referring to a type of green algae. [5]

The reproductive structures of Megaspora are apothecia, which are deeply immersed in the thalline warts (small, wart-like structures on the thallus). The apothecia have a thalline margin , a rim composed of thallus tissue. The true exciple , or the outer layer surrounding the apothecia, is thin and either colourless or pale straw-coloured, consisting of tightly packed, vertically aligned hyphae (fungal filaments). [5]

The epithecium , the uppermost layer of the apothecium, is brown-green and turns bright green when treated with a nitrogen-based reagent (N+). The hymenium, the spore-bearing layer, is colourless and turns blue with iodine (I+). The hypothecium , the layer beneath the hymenium, is also colourless. The hamathecium , which contains the paraphyses (sterile filaments among the asci), is richly branched and interconnected (anastomosing) without swollen tips, and is strongly conglutinate d (stuck together). [5]

The asci (spore-producing cells) are of the Biatora -type, containing 4 to 8 spores, and are clavate (club-shaped) or cylindric-clavate, with thin walls except towards the apex. The asci have a pale tholus (a thickened area at the tip) that reacts faintly with potassium/iodine (K/I). The ascospores are large, aseptate (without internal divisions), globose (spherical) to shortly ellipsoidal, colourless, and have uniformly thickened walls. [5]

Conidiomata (structures producing asexual spores) have not been observed in this genus. No lichen products have been detected through thin-layer chromatography. [5]

Habitat

Megaspora lichens typically grow on soil, bryophytes (mosses and liverworts), or plant litter on calcareous (chalky) substrates. They are rarely found growing on bark (corticolous). [5]

Species

Related Research Articles

<i>Psora</i> Genus of lichens

Psora is a genus of lichen-forming fungi in the family Psoraceae. Members of the genus are commonly called fishscale lichens. Lichens in the genus Psora generally have a squamulose thallus and anthraquinones in the hymenium. Photobiont partners of Psora lichens include members of the green algal genera Asterochloris, Chloroidium, Myrmecia, and Trebouxia.

<i>Aspicilia</i> Genus of lichens in the family Aspiciliaceae

Aspicilia is a genus of mostly crustose areolate lichens that grow on rock. Most members have black apothecia discs that are slightly immersed in the areolas, hence the common name"Given the same reason, the naming of Aspicilia is derived from the Greek word for "shield concave".

<span class="mw-page-title-main">Megasporaceae</span> Family of lichen-forming fungi

Megasporaceae are a family of fungi belonging to the order Pertusariales. Taxa are lichenized with green algae, and grow on rocks, often in maritime climates close to fresh water. Phylogenetic analysis has shown that this family is related to the Pertusariaceae, another family of lichens. The genus Aspicilia was moved here from the Hymeneliaceae.

<span class="mw-page-title-main">Pertusariales</span> Order of fungi

The Pertusariales are an order of fungi in the class Lecanoromycetes, comprising 8 families, 31 genera, and over 600 species, many of which form lichens. This diverse group is characterized by complex taxonomic history and ongoing phylogenetic revisions. Originally proposed by Maurice Choisy in 1949 and later formally published by the lichenologists David L. Hawksworth and Ove Eriksson in 1986, Pertusariales has undergone significant reclassification due to molecular phylogenetics studies. The order includes well-known genera such as Pertusaria and Ochrolechia, as well as families like Megasporaceae and Icmadophilaceae.

<i>Acarospora</i> Genus of fungi

Acarospora is a genus of mostly lichen-forming fungi in the family Acarosporaceae. Most species in the genus are crustose lichens that grow on rocks in open and arid places all over the world. They may look like a cobblestone road or cracked up old paint, and are commonly called cobblestone lichens or cracked lichens. They usually grow on rock, but some grow on soil (terricolous) or on other lichens. Some species in the genus are fungi that live as parasites on other lichens. Acarospora is a widely distributed genus, with about 128 species according to a 2008 estimate.

<i>Diploschistes</i> Genus of lichen

Diploschistes is a genus of lichen-forming fungi in the family Graphidaceae. Commonly known as crater lichens, members of the genus are crustose lichens with a thick, cracked (areolate) body (thallus) with worldwide distribution. The fruiting part (apothecia) are immersed in the thick thallus so as to have the appearance of being small "craters". The widespread genus contains about 43 species.

<i>Phaeophyscia</i> Genus of lichens

Phaeophyscia is a genus of lichen-forming fungi in the family Physciaceae.

<i>Placopyrenium</i> Genus of lichen

Placopyrenium is a genus of saxicolous (rock-dwelling), crustose lichens in the family Verrucariaceae.

<span class="mw-page-title-main">Fuscideaceae</span> Family of lichen-forming fungi

Fuscideaceae is a family of lichen-forming fungi in the order Umbilicariales. It contains five genera and about 55 species of crustose lichens.

Aderkomyces thailandicus is a species of corticolous (bark-dwelling), crustose lichen in the family Gomphillaceae. Found in the lower montane rainforests of Thailand, it was described as new to science in 2011.

<i>Lobothallia</i> Genus of fungi

Lobothallia is a genus of lichens in the family Megasporaceae. Species in the genus have foliose thalli that become crustose areolate in the center with age, and grow on calcareous to siliceous rocks. The crustose part of the body may keep its lower cortex, though not always. Dark brown to black apothecia may be sunken into the surface of the thallus, as indicated in the common name puffed sunken disk lichen. Members grow to 3–5 cm (1.2–2.0 in) or more radiating lobes (placodioid). The photobiont is green alga from the genus Trebouxia. The genus is represented in Eurasia, Asia, North Africa, Central America, western North America, and Australia.

Teuvoa is a genus of lichen-forming fungi in the family Megasporaceae. It was first classified by lichenologists Mohammad Sohrabi and Steven Leavitt in 2013, with Teuvoa uxoris assigned as the type species. This genus was delineated from the larger genus, Aspicilia, following a molecular phylogenetic analysis which revealed that the Aspicilia uxoris species group constituted a distinct lineage in the Megasporaceae. Initially containing three species, two additional species native to China were added in 2018. Teuvoa is characterised by its small ascospores and conidia, and the absence of secondary metabolites.

Halospora is a genus of lichenicolous (lichen-dwelling) fungi in the family Verrucariaceae. Species in the genus parasitise calcicolous crustose lichens, i.e., those that prefer lime-rich substrates.

<i>Piccolia</i> Genus of lichens

Piccolia is a small genus of crustose lichens in the class Lecanoromycetes. First circumscribed by Italian lichenologist Abramo Bartolommeo Massalongo in 1864, it contains ten species. Due to a lack of molecular data, it has not been assigned to an order or family.

Aspiciliopsis is a genus of lichen-forming fungi in the family Trapeliaceae. It has two species, both of which occur in the Southern Hemisphere.

Calogaya orientalis is a species of corticolous (bark-dwelling) and muscicolous lichen (moss-dwelling), crustose lichen in the family Teloschistaceae. It is found in arid steppe and desert habitats in Northwestern China, Iran, and Turkey. The thallus of this lichen is reduced, similar to species in the genus Athallia.

<i>Coniocarpon</i> Genus of lichens

Coniocarpon is a genus of lichen-forming fungi in the family Arthoniaceae. It has eight species of corticolous (bark-dwelling) lichens. This genus is distinct for its crystalline orange, red, and purple quinoid pigments in the ascomata that turn purple in potassium hydroxide solution, its colourless, transversely septate ascospores with large apical cells, and its rounded to lirellate ascomata.

<i>Puttea</i> Genus of lichens

Puttea is a genus of lichen-forming fungi with uncertain familial placement in the order Lecanorales. The genus comprises four species. Finnish lichenologists Soili Stenroos and Seppo Huhtinen established the genus Puttea in 2009 for the lichen species formerly known as Lecidea margaritella, which has undergone various reclassifications. Molecular phylogenetics analyses have shown that Puttea margaritella does not align closely with genera like Fellhanera or Micarea, but its precise familial placement remains uncertain. Puttea is characterized by an indistinct, lichenized thallus composed of delicate fungal filaments and small algal cells. Its minute, round, whitish apothecia lack a distinct margin, and the asci, or spore-producing cells, are thick-walled, club-shaped, and contain eight spores, showing specific reactions with iodine-based stains. The type species of the genus, Puttea margaritella, typically inhabits boreal forests, growing on the liverwort species Ptilidium pulcherrimum and sometimes on decaying wood or bark. Initially thought to be confined to Europe, it has since been found in North America, particularly in Alaska and Québec, extending its known range. The species is parasitic, damaging its host, and is considered rare within its distribution.

<i>Aspiciliella</i> Genus of lichens

Aspiciliella is a genus of lichen-forming fungi in the family Megasporaceae. It has four species. The genus is characterised by its crustose, rimose-areolate thallus that is partially continuous and has a K+ (red) reaction. The epihymenium is typically green to olive-green and turns light green when treated with N. Aspiciliella has eight-spored asci of the Aspicilia-type, containing ellipsoid, colourless, and simple ascospores.

<i>Aspilidea</i> Single-species lichen genus

Aspilidea is a fungal genus of uncertain familial placement in the subclass Ostropomycetidae. It contains the single species Aspilidea myrinii, a saxicolous (rock-dwelling) crustose lichen with a circumpolar distribution.

References

  1. Clauzade, G.; Roux, C. (1984). "Les genres Aspicilia Massal. et Bellemerea Hafellner & Roux". Bulletin de la Société Botanique du Centre-Ouest (in French). 15: 127–141.
  2. Wirth, V. (1987). Die Flechten Baden-Württembergs. Verbreitungsatlas (in German). Stuttgart: Verlag Eugen Ulmer. p. 511. ISBN   978-3-8001-3305-5.
  3. Arcadia, Linda in; Nordon, Anders (2012). "(2053) Proposal to conserve the name Megaspora verrucosa (Ach.) L. Arcadia & A. Nordin against M. verrucosa Hafellner & V. Wirth (lichenised Ascomycota)". Taxon. 61 (2): 464–465. doi:10.1002/TAX.612018. JSTOR   23210538.
  4. May, Tom C.; Lendemer, James C. (2023). "Report of the Nomenclature Committee for Fungi: 22". Taxon. 72 (6): 1356–1363. doi: 10.1002/tax.13099 .
  5. 1 2 3 4 5 6 Cannon, P.; Nordin, A.; Coppins, B.; Aptroot, A.; Sanderson, N.; Simkin, J. (2023). Pertusariales: Megasporaceae, including the genera Aspicilia, Aspiciliella, Circinaria, Lobothallia, Megaspora and Sagedia. Revisions of British and Irish Lichens. Vol. 34. p. 11.
  6. Zakeri, Zakieh; Gasparyan, Arsen; Aptroot, André (2016). "A new corticolous Megaspora (Megasporaceae ) species from Armenia". Willdenowia. 46 (2): 245–251. doi: 10.3372/wi.46.46205 .
  7. Haji Moniri, M.; Gromakova, A.B.; Lőkös, L.; Kondratyuk, S.Y. (2017). "New members of the Megasporaceae (Pertusariales, lichen-forming Ascomycota): Megaspora iranica spec. nova and Oxneriaria gen. nova". Acta Botanica Hungarica. 59 (3–4): 343–370. doi:10.1556/034.59.2017.3-4.5.
  8. Valadbeigi, Tahereh; Nordin, Anders; Tibell, Leif (2011). "Megaspora rimisorediata (Pertusariales , Megasporaceae), a new sorediate species from Iran and its affinities with Aspicilia sensu lato". The Lichenologist. 43 (4): 285–291. doi:10.1017/S0024282911000211.