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 ...

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 Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

). 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 A truffle is the fruiting body of a subterranean ascomycete fungus, predominantly one of the many species of the genus ''Tuber''. In addition to ''Tuber'', many other genera of fungi are classified as truffles including '' Geopora'', '' Pe ...

, 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 so ...

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 stem Stem or STEM may refer to: Plant structures * Plant stem, ...

'' and '' Gyromitra'' 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'' 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 boar The wild boar (''Sus scrofa''), also known as the wild swine, common wild pig, Eurasian wild pig, or simply wild pig, is a suid native to much of Eurasia and North Africa, and has been introduced to the Americas and Oceania. The species i ...

s, 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'', '' Talaromyces'' 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'' (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 c ...

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

Guignardia ''Guignardia'' is a genus of fungi in the family Botryosphaeriaceae. The genus name of ''Guignardia'' is in honour of Jean Louis Léon Guignard (1852–1928), who was a French pharmacist and botanist. The genus was circumscribed by Pierre Via ...

aesculi''.

References

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