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An ascocarp, or ascoma (PL: ascomata), is the fruiting body (sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are most commonly bowl-shaped (apothecia) but may take on a spherical or flask-like form that has a pore opening to release spores (perithecia) or no opening (cleistothecia). [1] [2] [ better source needed ]
The ascocarp is classified according to its placement (in ways not fundamental to the basic taxonomy). It is called epigeous if it grows above ground, as with the morels, while underground ascocarps, such as truffles, are termed hypogeous. The structure enclosing the hymenium is divided into the types described below (apothecium, cleistothecium, etc.) and this character is important for the taxonomic classification of the fungus. Apothecia can be relatively large and fleshy, whereas the others are microscopic—about the size of flecks of ground pepper.
An apothecium (plural: apothecia) is a wide, open, saucer-shaped or cup-shaped fruit body. It is sessile and fleshy. The structure of the apothecium chiefly consists of three parts: hymenium (upper concave surface), hypothecium, and excipulum (the "foot"). The asci are present in the hymenium layer. The asci are freely exposed at maturity. An example are the members of Dictyomycetes. Here the fertile layer is free, so that many spores can be dispersed simultaneously. The morel, Morchella, an edible ascocarp, not a mushroom, favored by gourmets, is a mass of apothecia fused together in a single large structure or cap. The genera Helvella and Gyromitra are similar.
A cleistothecium (plural: cleistothecia) is a globose, completely closed fruit body with no special opening to the outside. The ascomatal wall is called peridium and typically consists of densely interwoven hyphae or pseudoparenchyma cells. It may be covered with hyphal outgrowth called appendages. The asci are globose, deliquescent, and scattered throughout the interior cavity i.e. as in Eurotium or arising in tufts from the basal region of ascocarps as in Erysiphe. In this case the ascocarp is round with the hymenium enclosed, so the spores do not automatically get released, and fungi with cleistothecia have had to develop new strategies to disseminate their spores. The truffles, for instance, have solved this problem by attracting animals such as wild boars, which break open the tasty ascocarps and spread the spores over a wide area. Cleistothecia are found mostly in fungi that have little room available for their ascocarps, for instance those that live under tree bark, or underground like truffles.
Similar to a cleistothecium, a gymnothecium is a completely enclosed structure containing globose or pear-shaped, deliquescent asci. However, unlike the cleistothecium, the peridial wall of a gymnothecium consists of a loosely woven "tuft" of hyphae, often ornamented with elaborate coils or spines. Examples are the Gymnoascus , Talaromyces and the dermatophyte Arthroderma .
Perithecia are flask shaped structures opening by a pore or ostiole (short papilla opening by a circular pore) through which the ascospores escape. The ostiolar canal may be lined by hair-like structures called periphyses. The unitunicate asci are usually cylindrical in shape, borne on a stipe (stalk), released from a pore, developed from the inner wall of the perithecium and arise from a basal plectenchyma-centrum. Examples are members of Sphaeriales and Hypocreales. Perithecia are also found in Xylaria (Dead Man's Fingers, Candle Snuff), Nectria , Claviceps and Neurospora .
Sometimes the perithecia are "free" (individually visible from the outside), but in many species they are embedded in a dense sterile tissue of haploid cells called a stroma (plural: stromata). [3]
This is similar to a perithecium, but the asci are not regularly organised into a hymenium and they are bitunicate, having a double wall that expands when it takes up water and shoots the enclosed spores out suddenly to disperse them. Example species are Apple scab (Venturia inaequalis) and the horse chestnut disease Guignardia aesculi.
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 the Ascomycota are asexual, meaning that they do not have a sexual cycle 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.
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores, produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or species can occur in numbers of one, two, four, or multiples of four. In a few cases, the ascospores can bud off conidia that may fill the asci with hundreds of conidia, or the ascospores may fragment, e.g. some Cordyceps, also filling the asci with smaller cells. Ascospores are nonmotile, usually single celled, but not infrequently may be coenocytic, and in some cases coenocytic in multiple planes. Mitotic divisions within the developing spores populate each resulting cell in septate ascospores with nuclei. The term ocular chamber, or oculus, refers to the epiplasm that is surrounded by the "bourrelet".
Sordaria fimicola is a species of microscopic fungus. It is commonly found in the feces of herbivores. Sordaria fimicola is often used in introductory biology and mycology labs because it is easy to grow on nutrient agar in dish cultures. The genus Sordaria, closely related to Neurospora and Podospora, is a member of the large class Sordariomycetes, or flask-fungi. The natural habitat of the three species of Sordaria that have been the principal subjects in genetic studies is dung of herbivorous animals. The species S. fimicola is common and worldwide in distribution. The species of Sordaria are similar morphologically, producing black perithecia containing asci with eight dark ascospores in a linear arrangement. These species share a number of characteristics that are advantageous for genetic studies. They all have a short life cycle, usually 7–12 days, and are easily grown in culture. Most species are self-fertile and each strain is isogenic. All kinds of mutants are easily induced and readily obtainable with particular ascospore color mutants. These visual mutants aid in tetrad analysis, especially in analysis of intragenic recombination.
Erysiphales are an order of ascomycete fungi. The order contains one family, Erysiphaceae. Many of them cause plant diseases called powdery mildew.
Chlorociboria aeruginascens is a saprobic species of mushroom, commonly known as the green elfcup or the green wood cup because of its characteristic small, green, saucer-shaped fruit bodies. Although the actual fruit bodies are infrequently seen, the green staining of wood caused by the fungus is more prevalent.
This is a glossary of some of the terms used in phytopathology.
Xylaria polymorpha, commonly known as dead man's fingers, is a saprobic fungus. It is a common inhabitant of forest and woodland areas, usually growing from the bases of rotting or injured tree stumps and decaying wood. It has also been known to colonize substrates like woody legume pods, petioles, and herbaceous stems. It is characterized by its elongated upright, clavate, or strap-like stromata poking up through the ground, much like fingers. The genus Xylaria contains about 100 species of cosmopolitan fungi. Polymorpha means "many forms". As its name suggests, it has a very variable but often club-shaped fruiting body (stroma) resembling burned wood.
The Discinaceae are a family of ascomycete fungi, the best known members of which are the false morels of the genus Gyromitra. Originally erected by Erich Heinz Benedix in 1961, it was found to be a discrete clade in a molecular study of ribosomal DNA by mycologist Kerry O'Donnell in 1997. As of 2008, the family is thought to contain 5 genera and 58 species. As of 2022, the GBIF accepts Discina(Fr.) Fr., Gymnohydnotrya B.C.Zhang & Minter, 1989, GyromitraFr., 1849, HydnotryaBerk. & Broome and Maublancomyces. But calls NeogyromitraS.Imai and PseudorhizinaJacz. doubtful.
Cookeina is a genus of cup fungi in the family Sarcoscyphaceae, members of which may be found in tropical and subtropical regions of the world. Species may be found on fallen branches of angiosperms, trunks, and sometimes on fruits. The Temuans of Peninsular Malaysia are reported to use certain species from this genus as food, and also as a bait for fishing, where it is rubbed against the hook.
Badimiella is a genus of lichen-forming fungi in the family Pilocarpaceae. It has two species of foliicolous (leaf-dwelling) lichens.
Sphaerotheca castagnei is a species of ascomycete fungus in the family Erysiphaceae. A plant pathogen, it causes a form of powdery mildew.
Wynnea americana, commonly known as moose antlers or rabbit ears, is a species of fungus in the family Sarcoscyphaceae. This uncommon inedible species is recognizable by its spoon-shaped or rabbit-ear shaped fruit bodies that may reach up to 13 cm (5.1 in) tall. It has dark brown and warty outer surfaces, while the fertile spore-bearing inner surface is orange to pinkish to reddish brown. The fruit bodies grow clustered together from large underground masses of compacted mycelia known as sclerotia. In eastern North America, where it is typically found growing in the soil underneath hardwood trees, it is found from New York to Michigan south to Mexico. The species has also been collected from Costa Rica, India, and Japan.
Thelebolus is a genus of fungi in the Thelebolaceae family. Often considered related to Pezizales, 18S phylogenies show Thelebolales are a sister group to Pseudeurotiaceae and Leotiales. ITS is an adequate DNA barcode but there are only six variable sites in Thelebolus; β-tubulin is a recommended secondary barcode.
Ascodesmis nigricans is a coprophilous fungus that could be isolated from the dung of various animals. It was firstly introduced by Philippe Édouard Léon Van Tieghem, a French botanist, and was the type species of the genus Ascodesmis. It is an uncommon species but its development of the fruit body has been the subject of much laboratory study due to the easy nature of its cultivation. Ascodesmis nigricans is not pathogenic to human, animals or plants. This species has world-wide distribution.
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.
Asteridiella solani is a species of fungus in the family Meliolaceae, first described by Daniel McAlpine in 1897, who gave the following description:
On upper and under surfaces of leaves, leaf-stalks and branches; forming densely crowded, minute, black, generally orbicular, often confluent, easily detachable, brittle crusts, with surface of leaf beneath of a pale brown or pale reddish colour. Mycelium composed of an interosculating network of delicate, colourless, septate, luxuriantly branched hyphae, about 3 μ broad, and attached to matrix, gradually passing into the stouter coloured hyphae above it. Coloured hyphae dark brown, rigid, thick-walled, closely interwoven, septate, branched, 8-9½ μ broad, ultimate branchlets generally 1-septate, knobbed and paler in colour. Perithecia seated on crust in clusters, depressedly globose, black, rough with warty spines, 130-330 μ, the latter being the average full-grown size. Asci oblong to cylindrical, 4-spored usually, 38-64 X 13-26 μ (immature). Sporidia brown, oblong, 4-septate, slightly constricted at septa, rounded at both ends, 36-44 x 14-15 μ. Pycnidia globose, golden-brown, opening by circular mouth and wall composed of small polygonal cells 100-140 μ, along with perithecia. Sporules minute, subglobose or oval, hyaline or rarely brownish, 5½ x 3 μ or 4 μ diameter borne, on delicate hyaline, septate, branched hyphae.
On Solanum viride, R.Br.; Tintenbar, N.S.W. (Maiden).
The crusted mycelium is readily removed, and is steel-grey on the attached surface.The asci when ripe seem to burst within the perithecium, hence the difficulty of getting a mature ascus. The sporidia, which are at first colourless, then greenish and finally brown, often germinate even within the perithecium either from one or more segments. They are stained greenish-yellow by potassium-iodide-iodine, and the other contents of the perithecia are similarly stained.
Magnaporthe rhizophila is a fungus species in the family Magnaporthaceae. These dark mycelial fungi are common pathogens of cereal and grass roots. Rice blast is one disease known to be caused by M. rhizophila and presents with vascular discoloration in the host organism. The fungus lives best in drier humid conditions, explaining why it is most often found in the soils of Australia, South Africa, and the Southeastern United States.
This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found in glossary of biology and glossary of botany, among others. List of Latin and Greek words commonly used in systematic names and Botanical Latin may also be relevant, although some prefixes and suffixes very common in mycology are repeated here for clarity.
Pertusaria albineoides is a species of corticolous (bark-dwelling), crustose lichen in the family Pertusariaceae. Found on the Galápagos Islands, it was formally described as a new species in 2015 by Frank Bungartz, A.W.Archer, Alba Yánez-Ayabaca, and John Elix. The type specimen was collected on Alcedo Volcano at an altitude of 1,089 m (3,573 ft), where it was found growing on a partially shaded, rain- and wind-exposed trunk of Scalesia microcephala. The species epithet refers to the similarity to the species Pertusaria albinea, from which it differs by having thin-walled ellipsoid-shaped ascospores that are longer and narrower.