Oletheriostrigula | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Dothideomycetes |
Order: | Strigulales |
Family: | Strigulaceae |
Genus: | Oletheriostrigula Huhndorf & R.C.Harris (1996) |
Species: | O. papulosa |
Binomial name | |
Oletheriostrigula papulosa | |
Synonyms [1] | |
Oletheriostrigula is a fungal genus in the family Strigulaceae. [4] It comprises the single species Oletheriostrigula papulosa. [5] This microscopic fungus was first described in 1848 and has undergone several taxonomic reclassifications before being placed in its own genus in 1996. Unlike the vast majority of the Strigulaceae, O. papulosa does not form a symbiotic relationship with algae. It produces small, spherical fruiting bodies (ascomata) that grow on dead plant material, particularly on plants with durable or persistent leaves. The fungus has a widespread distribution, favouring warm climates, and plays a role in decomposition processes. O. papulosa is characterised by its unique combination of morphological features, including apically free paraphyses with bulbous tips, and its ability to produce both sexual and asexual spores.
Oletheriostrigula is a monospecific genus of non lichen-forming fungi, containing the single species Oletheriostrigula papulosa. The genus was erected in 1996 by mycologists Sabine Huhndorf and Richard C. Harris to accommodate the species previously known as Massarina papulosa. This species was originally described by the French mycologists Michel Charles Durieu de Maisonneuve and Camille Montagne in 1848; they classified it in the genus Sphaeria. [6] The taxon was shuffled to various genera over the next decades of its taxonomic history, including Leptosphaeria , Metasphaeria , Sphaerulina , Leptosphaerella , and Massarina . [1]
The genus name Oletheriostrigula reflects its close relationship to the lichen genus Strigula , while also indicating its non-lichenised nature. Unlike Strigula species, which form symbiotic relationships with algae, Oletheriostrigula does not contain photosynthetic partners and is therefore not considered a true lichen. [7]
Oletheriostrigula is placed within the family Strigulaceae, which primarily consists of lichenised fungi. It is notable for being the only non-lichenised member of this family. The genus shares several characteristics with Strigula, including: [7]
However, Oletheriostrigula differs from Strigula in its lack of lichenisation and some specific morphological features. The placement of this species in its own genus was necessitated by its unique combination of characteristics, particularly the presence of apically free paraphyses with slightly bulbous tips, which is incompatible with its previous placement in the genus Massarina. [7]
Oletheriostrigula papulosa is a microscopic fungus that, despite its classification within a family of predominantly lichens, does not form a symbiotic relationship with algae, setting it apart from true lichens. The fungus manifests as small, rounded structures called ascomata, which are nearly spherical in shape, measuring 170–250 μm in diameter and 130–230 μm in height. These ascomata are thickly scattered across the plant surface, appearing either individually or in small groups, and are surrounded by pale brown fungal threads known as hyphae. Each ascoma features a short, broad, rounded protrusion called a papilla that contains a circular opening (an ostiole) through which spores are released. [7]
The internal structure of the ascoma is complex, with an ascomatal wall composed of small, polygonal to elongated cells. This wall is 20–32 μm thick, becoming thicker near the apex, with outer layers that are brown and inner layers that are colourless, or hyaline. Within the ascoma, thin, thread-like structures called paraphyses can be found between the spore-producing sacs. These paraphyses narrow from 2.5–3 μm at the base to 1 μm at the tip, which is slightly bulbous. The spore-producing sacs (asci) are obovate in shape, resembling an egg with the narrow end at the base. They measure 51–81 μm in length and 11.4–17.1 μm in width, are thick-walled with a rounded, thickened apex, and possess a double wall, a feature described as bitunicate . Each ascus contains eight spores arranged in one to three rows. [7]
The reproductive spores ( ascospores ) of O. papulosa are fusiform to clavate -oblong in shape, wider at one end and tapering at the other. They measure 18.5–26.5 μm in length and 5.6–9.6 μm in width. These spores are colourless to nearly colourless and are usually divided by four (occasionally five) cross-walls called septa. A characteristic feature is the constriction at the middle septum and the thickened outer wall surrounding the spore, which appears sheath-like. In addition to its sexual reproductive structures, O. papulosa can also produce an asexual stage known as a Diplodia state. This stage forms simpler spores called conidia and has been observed both in laboratory cultures and occasionally on host plant tissues in nature. [7]
Oletheriostrigula papulosa is a widespread fungus that inhabits dead plant material, particularly favouring plants with durable or persistent leaves. This fungus is commonly found growing on dead stems and leaves of various host plants, where it plays a role in the decomposition process. The species shows a preference for warm climates, suggesting a primarily tropical to subtropical distribution. However, its exact geographical range has not been fully documented. It has been reported from diverse locations, including Algeria, where it was first described, and California in the United States. [7]
Oletheriostrigula papulosa papulosa demonstrates a broad host range, colonising a variety of plant species. It has been observed on both evergreen and deciduous plants, but seems to favour those with tough, long-lasting foliage. Some of the documented host plants include species of Ilex (holly), Washingtonia (fan palms), and Yucca . Other reported hosts encompass a wide range of plant families, including citrus ( Citrus aurantium ), ivy ( Hedera helix ), fan palm ( Chamaerops humilis ), and various conifers such as Araucaria imbricata . [7]
The fungus does not appear to cause significant damage to living plant tissues, as it is primarily found on dead or dying parts of its host plants. This suggests that O. papulosa functions as a saprobe, an organism that obtains its nutrients from dead organic matter. In this ecological role, it likely contributes to nutrient cycling in its habitat by breaking down complex plant materials. [7]
The ability of O. papulosa to produce both sexual (ascospores) and asexual (conidia) spores potentially allows it to disperse and colonize new substrates efficiently. This dual reproductive strategy, combined with its ability to thrive on a wide range of host plants, likely contributes to its ecological success and widespread distribution in suitable habitats. [7]
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus", a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of Ascomycota are asexual and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, brewers' and bakers' yeast, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens such as Cladonia belong to the Ascomycota.
The Arthoniaceae are a family of lichenized, lichenicolous and saprobic fungi in the order Arthoniales. The Arthoniaceae is the largest family of Arthoniales, with around 800 species. Most species in Arthoniaceae belong in Arthonia which is the largest genus with 500 species. The second and third largest genus is Arthothelium with 80 species, and Cryptothecia with 60 species.
Gloeoheppiaceae is a family of ascomycete fungi in the order Lichinales. The family contains ten species distributed amongst three genera. Most species are lichenised with cyanobacteria. Species in this family are mostly found in desert areas. Modern molecular phylogenetics analysis casts doubt on the phylogenetic validity of the family, suggesting a more appropriate placement of its species in the family Lichinaceae.
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.
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Buellia is a genus of mostly lichen-forming fungi in the family Caliciaceae. The fungi are usually part of a crustose lichen. In this case, the lichen species is given the same name as the fungus. But members may also grow as parasites on lichens (lichenicolous). The algae in the lichen is always a member of the genus Trebouxia.
Aquamarina is a fungal genus in the class Dothideomycetes. It is a monotypic genus, containing the single marine species Aquamarina speciosa, originally found in North Carolina, and distributed in the Atlantic Coast of the United States. The bluish-green species fruits exclusively in the lower parts of dying culms of the saltmarsh plant Juncus roemerianus.
Massarina carolinensis is a species of fungus in the Lophiostomataceae family. The species is found exclusively on the lower parts of the culms of the saltmarsh Juncus roemerianus on the Atlantic Coast of North Carolina.
Collariella bostrychodes is a fungal decomposer of lignin and carbohydrate in the family Chaetomiaceae commonly found in soil and dung. The fungus is distinguished by a darkened collar-like ostiole around the ostiolar pore, giving the fungus its name. The fungus is highly variable in shape and form, giving raise to the belief that there are two subclades in the species. The ascospores range from lemon-shaped to nearly spherical with slightly pointed ends. It can grow to be pale green and later turn pale bluish grey or olivaceous with age. The fungus produces the toxic secondary metabolite, chaetochromin.
Botryotrichum piluliferum is a fungal species first identified in 1885 by Saccardo and Marchal. It was discovered to be the asexual state of a member of the ascomycete genus, Chaetomium. The name B. piluliferum now applies to the fungus in all its states. B. piluliferum has been found worldwide in a wide range of habitats such as animal dung and vegetation. The colonies of this fungus start off white and grow rapidly to a brown colour. The conidia are smooth and white. B. piluliferum grows optimally at a temperature of 25–30 °C and a pH of 5.5.
Cercophora areolata is a member of the Ascomycota division, and is grouped into the Lasiosphaeriaceae family based on morphology. C. areolata is a coprophilous fungus that has been most recently isolated from porcupine dung. Defining features of C. areolata include: 1) ovoid-conical, glabrous ascomata, 2) black, carbonaceous, areolate peridium and 3) clavate-shaped, single-walled asci. From studies on C. areolata, this fungus produces multiple antifungal compounds, which inhibit other competitor fungi.
Taitaia is a single-species fungal genus in the family Gomphillaceae. It was circumscribed in 2018 to contain the species Taitaia aurea, a lichenicolous (lichen-dwelling) fungus. This species is characterized by aggregated ascomata with yellow margins, and salmon-red discs that originate from a single base. It is known only from a few sites in Kenya's tropical lower-mountain forests, where it grows on thalli of the lichen Crocodia.
Opegrapha verseghyklarae is a little-known species of lichenicolous (lichen-eating) fungus in the family Opegraphaceae. It is found in the Russian Far East, where it grows on the thalli and apothecia of the crustose lichen Ochrolechia pallescens.
Thelenellaceae is a family of lichen-forming fungi. It is the sole family in the monotypic order Thelenellales, and contains three genera and about 50 species.
Protothelenella is a genus of fungi in the family Protothelenellaceae. It contains 11 species, some of which form lichens. Protothelenella species have a crustose thallus with spherical to pear-shaped, dark brown to blackish perithecia. Microscopic characteristics of the genus include bitunicate asci with an amyloid tholus, and ascospores that are colourless and contain multiple internal partitions. Some species grow on acidic substrates including rocks, soil, bryophytes, plant detritus or rotten wood. Other species are lichenicolous (lichen-dwelling), growing on species of Solorina, Peltigera, Pseudocyphellaria, or Cladonia.
Aspiciliopsis is a genus of lichen-forming fungi in the family Trapeliaceae. It has two species, both of which occur in the Southern Hemisphere.
Stigmidium cerinae is a species of lichenicolous (lichen-dwelling) fungus in the family Mycosphaerellaceae. It was formally described as a new species in 1994 by mycologists Claude Roux and Dagmar Triebel. The type specimen was collected in Austria from the apothecia of the muscicolous (moss-dwelling) species Caloplaca stillicidiorum. It infects lichens in the genus Caloplaca, and more generally, members of the family Teloschistaceae. Infection by the fungus results in bleaching of the host hymenium.
Macroconstrictolumina is a genus of lichen-forming fungi in the family Trypetheliaceae. It has four species.
Glyphopsis is a fungal genus of uncertain familial placement in the order Arthoniales. It contains the single species Glyphopsis aurantiodisca, a bark-dwelling crustose lichen found in New Caledonia. Both the genus and species were described as new to science in 2014 by the Dutch lichenologist André Aptroot.
Megaloblastenia is a genus of crustose lichen-forming fungi in the family Megalosporaceae, comprising three species. Proposed by Dutch lichenologist Harrie Sipman in 1983, the genus is characterised by its thick, ecorticate thallus ranging from pale whitish-grey to yellowish, and its disc-like fruiting bodies (apothecia) that can be biatorine or lecideine. Megaloblastenia lichens form a symbiotic relationship with Dictyochloropsis algae, produce hyaline, bicellular ascospores with polaribilocular structure, and contain chemical compounds such as zeorin, pannarin, or usnic acid. Found in Australasia and South America, these lichens typically grow as epiphytes on trees in moist forests within temperate to tropical oceanic climates.