Ascocarp

{{Short description|Fruiting body of an ascomycete fungus}} {{Use dmy dates|date=October 2023}} {{more citations needed|date=October 2014}}

An '''ascocarp''', or '''ascoma''' ({{plural form}}: '''ascomata'''), is the fruiting body ([[sporocarp (fungi)|sporocarp]]) of an [[ascomycete]] phylum fungus. It consists of very tightly interwoven [[hypha]]e and millions of embedded [[ascus|asci]], each of which typically contains four to eight [[ascospore]]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).<ref>{{cite encyclopedia |url=http://www.britannica.com/EBchecked/topic/37968/ascocarp |title=ascocarp (fruiting structure of fungi) |encyclopedia=[[Encyclopædia Britannica]] |access-date=23 November 2020}}</ref><ref>{{cite web |url=http://www.clinicalfungi.org/Biolomics.aspx?Table=Glossary&Genlist=t |archive-url=https://web.archive.org/web/20191028010408/http://www.clinicalfungi.org/Biolomics.aspx?Table=Glossary&Genlist=t |url-status=dead |archive-date=28 October 2019 |url-access=registration |title=Atlas of Clinical Fungi (glossary) |access-date=11 September 2019 |publisher=[[Westerdijk Institute|Westerdijk Fungal Biodiversity Institute]]}}</ref>{{Better source needed|reason=Reference does not appear at the link specified. The reference may still exist at the cited website, but requires registration to access, and Wayback Machine archive displays a non-functioning web page.|date=November 2020}}

== Classification ==  {{multiple image | align = right | direction = horizontal | image1 = Ascomata.svg | alt1 = | caption1 = '''Tissue arrangement'''. The [[peridium]] is indicated in pink. Note the cylindrical asci in the two left types (apothecium, peri-/pseudothecium), and the globose asci in the two right types (cleistothecium, gymnothecium). | image2 = Ascomata_relative.svg | alt2 = | caption2 = '''Relative sizes''' of apothecium, peri-/pseudothecium and cleisto-/gymnothecium (from left to right) }} The ascocarp is classified according to its placement (in ways not fundamental to the basic [[Taxonomy (biology)|taxonomy]]). It is called ''epigeous'' if it grows above ground, as with the [[morel]]s, 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.

== Apothecium == [[Image:Ascocarp2.png|thumb|middle|270px|Diagram of an apothecium showing sterile tissues as well as developing and mature asci]] 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, favored by gourmets, is a mass of apothecia fused together in a single large structure or cap. The genera ''[[Helvella]]'' and ''[[Gyromitra]]'' are similar.

{{gallery|mode=packed |Smardz-Morchella-Ejdzej-2006.jpg|The ascocarp of a [[morel]] contains numerous apothecia. }}

== 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 [[boar|wild boar]]s, which break open the 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 == [[Image:Nectria.jpg|thumb|Perithecia of ''Nectria'']]

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 {{anchor|stroma}}''stroma'' (plural: stromata).<ref name="Laessoe2019">See page 30 and glossary of {{cite book |first1=H. |last1=Læssøe |first2=Jens |last2=Petersen |title=Fungi of Temperate Europe |publisher=Princeton University Press |year=2019 |page=30 |isbn=9780691180373 }}</ref> Some fungi have a shield-shaped layer called a clypeus over their perithecia.<ref>{{cite web |last1=Grgurinovic |first1=C. A. |title=Clypeus |url=https://www.dcceew.gov.au/science-research/abrs/online-resources/glossaries/fungi |website=Fungi of Australia Glossary |access-date=21 February 2025 |date=1996}}</ref>

== Pseudothecium == {{multiple image | align = right | total_width = 449 | image_gap = 10 | image1 = Perithecium no text.PNG | caption1 = Diagram of a pseudothecium. Eight ascospores (green) are typically present in each ascus. | image2 = Leptosphaerulina sp.jpg | caption2 = Bitunicate asci in the pseudothecium of ''Leptosphaerulina'' sp. }}

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''.

== See also == * [[Basidiocarp]] * [[Conidium]]

== References == {{reflist}}

[[Category:Mycology]] [[Category:Fungal morphology and anatomy]] [[Category:Fungal fruiting body types]]

[[de:Schlauchpilze#Das Ascokarp]]