An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an

ascomycete 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 defi ...

phylum fungus. It consists of very tightly interwoven

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

e and millions of embedded

asci ASCI or Asci may refer to: * Advertising Standards Council of India * Asci, the plural of ascus, in fungal anatomy * Accelerated Strategic Computing Initiative * American Society for Clinical Investigation * Argus Sour Crude Index * Association of ...

, each of which typically contains four to eight

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. 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).

Classification

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

morel ''Morchella'', the true morels, is a genus of edible sac fungi closely related to anatomically simpler cup fungi in the order Pezizales (division Ascomycota). These distinctive fungi have a honeycomb appearance due to the network of ridges wi ...

s, while underground ascocarps, such as truffles, are termed ''hypogeous''. The structure enclosing 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 ...

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.

Apothecium

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: ''

'' (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

, ''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 ''Helvella'' is a genus of ascomycete fungus of the family Helvellaceae. The mushrooms, commonly known as elfin saddles, are identified by their irregularly shaped caps, fluted stems, and fuzzy undersurfaces. They are found in North America and ...

'' and ''

Gyromitra ''Gyromitra'' () is a genus of about 18 species of ascomycete fungi. They are a false morel - a frequently toxic mushroom that can be mistaken for edible mushrooms of the genus ''Morchella'' (morels). Taxonomy The name ''Gyromitra'' comes from ...

'' are similar.

Cleistothecium

A cleistothecium (plural: cleistothecia) is a globose, completely closed fruit body with no special opening to the outside. The ascomatal wall is called ''

peridium The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of gasteroid fungi. Description Depending on the species, the peridium may vary from being paper-thin to thick and rubbe ...

'' 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.

Gymnothecium

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 ''Gymnoascus'' is a genus of fungi within the Gymnoascaceae family. The genus, widely distributed in northern temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), whi ...

'', ''

Talaromyces ''Talaromyces'' is a genus of fungi in the family Trichocomaceae. Described in 1955 by American mycologist Chester Ray Benjamin, species in the genus form soft, cottony fruit bodies (ascocarps) with cell walls made of tightly interwoven hyphae. ...

'' and the dermatophyte '' Arthroderma''.

Perithecium

Perithecia are flask shaped structures opening by a pore or ''

ostiole An ''ostiole'' is a small hole or opening through which algae or fungi release their mature spores. The word is a diminutive of "ostium", "opening". The term is also used in higher plants, for example to denote the opening of the involuted ...

'' (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 The Hypocreales are an order of fungi within the class Sordariomycetes. In 2008, it was estimated that it contained some 237 genera, and 2647 species in seven families. Since then, a considerable number of further taxa have been identified, in ...

. Perithecia are also found in ''

Xylaria ''Xylaria'' is a genus of ascomycetous fungi commonly found growing on dead wood. The name comes from the Greek ''xýlon'' meaning ''wood'' (see xylem). Two of the common species of the genus are '' Xylaria hypoxylon'' and '' Xylaria polymorph ...

'' (Dead Man's Fingers, Candle Snuff), ''

Nectria ''Nectria'' is a genus of Ascomycete fungi. They are most often encountered as saprophytes on decaying wood but some species can also occur as parasites of trees, especially fruit trees (for example apple) and a number of other hardwood trees. ...

'', ''

Claviceps Ergot ( ) or ergot fungi refers to a group of fungi of the genus ''Claviceps''. The most prominent member of this group is ''Claviceps purpurea'' ("rye ergot fungus"). This fungus grows on rye and related plants, and produces alkaloids that ca ...

'' and ''

Neurospora ''Neurospora'' is a genus of Ascomycete fungi. The genus name, meaning "nerve spore" refers to the characteristic striations on the spores that resemble axons. The best known species in this genus is ''Neurospora crassa'', a common model organi ...

''. 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).See page 30 and glossary of

Pseudothecium

This is similar to a perithecium, but the asci are not regularly organised into a hymenium and they are

bitunicate 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 ...

, 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 Apple scab is a common disease of plants in the rose family (Rosaceae) that is caused by the ascomycete fungus '' Venturia inaequalis''. While this disease affects several plant genera, including ''Sorbus, Cotoneaster,'' and '' Pyrus'', it is m ...

(''Venturia inaequalis'') and the horse chestnut disease '' Guignardia aesculi''.

References

{{Fungus Mycology Fungal morphology and anatomy de:Schlauchpilze#Das Ascokarp