''Auricularia mesenterica'', commonly known as the tripe fungus, is a species of

fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

in the family

Auriculariaceae The Auriculariaceae are a family (biology), family of fungi in the order (biology), order Auriculariales. Species within the family were formerly referred to the "heterobasidiomycetes" or "jelly fungi", since many have gelatinous basidiocarps (fr ...

Basidiocarps In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...

(fruit bodies) are gelatinous and typically formed in coalescing tiers on stumps and logs. They are partly pileate, with hirsute, zoned caps, and partly

resupinate Resupination is derived from the Latin word ''resupinus'', meaning "bent back with the face upward" or "on the back". "Resupination" is the noun form of the adjective "resupine" which means "being upside-down, supine or facing upward". The word " ...

, with smooth to wrinkled undersurfaces that spread over the wood. ''Auricularia mesenterica'' is a

saprotroph Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ...

on dead

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

trees and shrubs. The species is restricted to Europe and Central Asia.

Taxonomy and etymology

''Auricularia mesenterica'' was described from England in 1785 by James Dickson as ''Helvella mesenterica'' and transferred to the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Auricularia'' by

Christiaan Hendrik Persoon Christiaan Hendrik Persoon (31 December 1761 – 16 November 1836) was a Cape Colony mycologist who is recognized as one of the founders of mycology, mycological Taxonomy (biology), taxonomy. Early life Persoon was born in Cape Colony at ...

in 1822. The species was considered to be cosmopolitan and was subsequently applied to collections from America, Asia, and Australia as well as Europe.

Molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

research, based on

cladistic Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...

analysis of

DNA sequences A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the ...

, has however shown that ''Auricularia mesenterica'' (as previously understood) is a complex of related species and that ''A. mesenterica''

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

is confined to Europe and Central Asia, with superficially similar but distinct species occurring elsewhere. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

is a

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

adjective formed from the

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

word (''mesentérion''), "middle intestine", from (''meso-'', "middle, center") and (''énteron'', "intestine"), referring to its shape.

Description

This species forms bracket-like fruit bodies that first appear pale, rubbery, and button-like, expanding to typically across and hardening with age. The fruit bodies often merge into compound structures sometimes running along fallen trunks and branches for more than . The upper surface is grey to brown or buff,

tomentose Trichomes (; ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

hispid Trichomes (; ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

with concentric zones, while the underside is thickly gelatinous, irregularly folded radially and reddish brown. The spore print is white. Microscopically the

basidia A basidium (: basidia) is a microscopic spore-producing structure found on the hymenophore of reproductive bodies of basidiomycete fungi. The presence of basidia is one of the main characteristic features of the group. These bodies are also ...

are auricularioid (tubular with three lateral septa) and the basidiospores are allantoid (sausage-shaped), 14 to 17 by 4.5 to 5

μm The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...

Distribution and habitat

Originally described from England, the species is known to occur throughout Europe and into Central Asia as far as Uzbekistan. Basidiocarps are formed on various deciduous tree stumps and logs.

Similar species

Other species in the ''Auricularia mesenterica'' complex include '' Auricularia brasiliensis'' in South America, '' A. pusio'' in Australia, '' A. africana'' in East Africa, and '' A. asiatica'', '' A. orientalis'', '' A. srilankensis'', and '' A. submesenterica'' in Asia. Other species of ''Auricularia'' lack the zoned, hirsute upper surface found in the ''A. mesenterica'' complex. Some unrelated ''

Stereum ''Stereum'' is the type genus of the Stereaceae family of fungi, in the Russulales order. Common names for species of this genus include leaf fungus, wax fungus, and shelf fungus. Fungi having a shape similar to a ''Stereum'' are said to have a s ...

'' species may have similarly zoned caps, but their fruit bodies are leathery (not gelatinous) and their undersurfaces are often yellowish to orange.

Uses

Before the fruit body fully matures and hardens, young specimens are said to be

edible An edible item is any item that is safe for humans to eat. "Edible" is differentiated from " eatable" because it does not indicate how an item tastes, only whether it is fit to be eaten. Nonpoisonous items found in nature – such as some mushroo ...

, but in some local populations, these fungi tend to

bioaccumulate Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Th ...

high levels of heavy metals from their environment. ''A. mesenterica'' has shown to have high levels of

phenols In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (− O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds ar ...

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

s, and

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

activity, having potential as

antitumor Cancer treatments are a wide range of treatments available for the many different types of cancer, with each cancer type needing its own specific treatment. Treatments can include surgery, chemotherapy, radiation therapy, hormonal therapy, targe ...

agent.

References

{{Taxonbar, from=Q127357 Auriculariales Taxa named by James Dickson (botanist) Fungi described in 1785 Fungi of Europe Fungus species