''Megalospora'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

in the family

Megalosporaceae The Megalosporaceae are a family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Division or divider may refer to: Mathematics *Division (mathematics), the inverse of multiplication *Division algorithm, a ...

Taxonomy

The genus was

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

in 1843 by Prussian botanist

Franz Meyen Franz Julius Ferdinand Meyen (28 June 1804 – 2 September 1840) was a Prussian physician and botanist. Meyen was born in Tilsit, East Prussia. In 1830 he wrote ''Phytotomie'', the first major study of plant anatomy. Between 1830 and 1832, he too ...

, with '' Megalospora sulphurata'' assigned as the type, and at that time, only species. The genus was then largely defined on the basis of the structure of the apothecia. In 2012,

Gintaras Kantvilas Gintaras Kantvilas (born 1956) is an Australian lichenologist, who earned his Ph.D in 1985 from the University of Tasmania with a thesis entitled ''Studies on Tasmanian rainforest lichens''. He has authored over 432 species names, and 167 gener ...

and H. Thorsten Lumbsch synonymized the genus ''Austroblastenia'' (which contained two species) with ''Megalospora'', based on both

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

and molecular phylogeny.

Description

''Megalospora'' is characterised by its large, bicellar

ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...

s. Other features include the

crustose Crustose is a 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 substrates at all points. ''Crustose'' is found on rocks and ...

thallus Thallus (plural: 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. Many of these organisms wer ...

, the lecideine apothecia, and the presence of oil droplets in the

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 others some ...

. The

photobiont A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

l genus ''

Dictyochloropsis ''Dictyochloropsis'' is a genus of unicellular green alga of the phylum Chlorophyta. This genus consists of free-living algae which have a reticulate (net-like) chloroplast that varies slightly in morphology between species, and that when mature a ...

''. ''Megalospora'' species are usually distinguished based on the type of ascospore,

chemistry, and the presence or absence of reproductive

propagule In biology, a propagule is any material that functions in propagating an organism to the next stage in its life cycle, such as by dispersal. The propagule is usually distinct in form from the parent organism. Propagules are produced by organisms ...

s such as

isidia An isidium is a vegetative reproductive structure present in some lichens. Isidia are outgrowths of the thallus surface, and are corticated (i.e., containing the outermost layer of the thallus), usually with a columnar structure, and consisting o ...

and

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 o ...

Species

, Species Fungorum accepts 22 species of ''Megalospora''. *'' Megalospora albomarginata'' –

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

*'' Megalospora atrorubricans'' *'' Megalospora australiensis'' *'' Megalospora austropacifica'' –

Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...

*'' Megalospora caraibica'' – Jamaica *'' Megalospora clandestina'' – Tasmania *'' Megalospora disjuncta'' – New Zealand *'' Megalospora flavoexcipulata'' – Java *'' Megalospora galactocarpa'' *'' Megalospora galapagoensis'' *'' Megalospora imshaugii'' – Jamaica *'' Megalospora javanica'' – Java *'' Megalospora lopadioides'' –

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

*'' Megalospora melanodermia'' *'' Megalospora occidentalis'' –

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

*'' Megalospora pauciseptata'' *'' Megalospora porphyritis'' *'' Megalospora pulverata'' – Tasmania *'' Megalospora pupa'' *'' Megalospora queenslandica'' *'' Megalospora reniformis'' *'' Megalospora subtuberculosa'' *'' Megalospora sulphurata'' – widespread *'' Megalospora tuberculosa''

References

{{Taxonbar, from=Q10579687 Teloschistales Lichen genera Teloschistales genera Taxa described in 1843 Taxa named by Franz Meyen