Gomphus clavatus
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Gomphus clavatus, commonly known pig's ears or violet chanterelle, as is an edible species of fungus in the genus Gomphus, family Gomphaceae native to Eurasia and North America. The fruit body is vase- or fan-shaped with wavy edges to its rim, and grows up to Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). wide and Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). tall. The upper surface or cap is orangish-brown to lilac, while its lower surface, the hymenium, is covered in wrinkles and ridges rather than gills or pores, and is a distinctive purple colour.
Typically found in coniferous forests, G. clavatus is mycorrhizal, and is associated with tree species in a variety of coniferous genera, particularly spruces and firs. It is more common at elevations of greater than Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value)., in moist, shady areas with plenty of leaf litter. Although widespread, G. clavatus has become rare in many parts of Europe and extinct in Great Britain. It has been placed on the national Red Lists of threatened fungi in 17 European countries and is one of 33 species proposed for international conservation under the Bern Convention.
Contents
Taxonomy
German naturalist Jacob Christian Schäffer described Elvela (subsequently Helvella) purpurascens in 1774. In 1796, mycologist Christian Hendrik Persoon described G. clavatus as Merulius clavatus, noting that it grew in grassy locations in woods. He noted it was the same species that Schaeffer had described.[3] The specific epithet—derived from the Latin word clavi (club) and meaning "club-shaped"[4]—refers to the shape of young fruit bodies.[5]
British botanist Samuel Frederick Gray transferred the violet chanterelle to the genus Gomphus in 1821.[6] The starting date of fungal taxonomy had been set as January 1, 1821, to coincide with the date of the works of the 'father of mycology', Swedish naturalist Elias Magnus Fries, which meant the name required sanction by Fries (indicated in the name by a colon) to be considered valid. Thus the species was written as Gomphus clavatus (Pers.: Fr.) Gray. A 1987 revision of the International Code of Botanical Nomenclature set the starting date at May 1, 1753, the date of publication of Linnaeus' work, the Species Plantarum.[7] Hence, the name no longer requires the ratification of Fries' authority.[2] Fries himself classified Gomphus as a tribe within the genus Cantharellus in his 1821 work Systema Mycologicum.[8]
The violet chanterelle was classified in the genus Nevrophyllum in 1886.[9] Alexander H. Smith treated Gomphus as a section within Cantharellus in his 1947 review of chanterelles in western North America, as he felt there were no consistent characteristics that distinguished the two genera.[10] In 1966 E.J.H. Corner described a small-spored variety, G. clavatus var. parvispora, from specimens collected in Uganda;[11] it is not considered to have independent taxonomic significance.[12]
Research combining the use of phylogenetic analyses of DNA sequences and more traditional morphology-based characters has resulted in a reshuffling of the species concept in Gomphus;[13] as a result, G. clavatus is currently considered the only Gomphus species in North America.[14] Comparison of the DNA sequences of species Gomphus brevipes and Gomphus truncatus has shown them to be genetically identical to G. clavatus, and they may be treated as synonyms.[13]
Gomphus clavatus is commonly known as pig's ears, alluding to the violet underside and yellowish cap of the fruit bodies,[6] although this vernacular name is also used for Discina perlata.[15] Other English common names for this species include clustered chanterelle and violet chanterelle.[16] In Nepal in the Sherpa language it is known as Eeshyamo ("mother-in-law"), as its imposing fruit body is reminiscent of a mother-in-law, who has a dominant role in the Sherpa family.[17]
Description
The basidiocarps, or fruit bodies, of immature Gomphus clavatus are club-shaped and have one cap or pileus, but later spread out and have a so-called merismatoid appearance—several vase-shaped caps rising from a common stem. The fruit body is up to Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). wide and Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). tall, fan-shaped with wavy edges. The upper surfaces of the fruit bodies are covered with brown hyphae that form small, distinct patches towards the margin, but combine to form a continuous felt-like tomentum over the center of the cap. The color of the upper cap surface is orange-brown to violet, but later in age fades to a lighter brown.[18] The lower spore-bearing surface—the hymenium—is wrinkled, often with folds and pits, and violet to brown in color. The solid stem, which is continuous with the cap,[19] is Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). wide, Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). tall,[10] and covered with fine hairs (tomentum) that become more coarse (hispid) towards the base. It is often compound, with several fruit bodies arising from the basal portion. Fruit bodies may bruise reddish-brown where handled.[20] The flesh can be whitish-pink to lilac or cinnamon-buff. Thick under the centre of the cap, it thins out towards the margins.[10] The taste and odor are mild. The spore print is yellow to orange-yellow.[21]
Basidiospores are elliptical, wrinkled or slightly warted, and 10–14 by 5–7.5 μm.[18] The spores are nonamyloid, meaning they have a negative color reaction with the iodine in Melzer's reagent. The spore-bearing structures, the basidia, are elongated or club-shaped, hyaline (glassy or translucent), and four-spored, with dimensions of 60–90 by 8.5–11.5 μm.[22] G. clavatus does not contain cystidia, the sterile cells associated with basidia in many species. Clamp connections are present.[22]
Similar species
Gomphus crassipes, found in Spain and North America, can only be reliably distinguished from G. clavatus with the use of a microscope.[23] Pseudocraterellus pseudoclavatus (formerly classified in Gomphus) is a lookalike species that grow under conifers in the central United States and westward,[24] also differing on microscopic characters and reaction to potassium hydroxide.[10]
Habitat, distribution, and conservation
Gomphus clavatus grows singly, in clusters or clumps, or even occasionally fairy rings,[10] on the ground, typically in coniferous forests, and with a preference for deep leaf litter in moist, shady areas.[21] Fruit bodies are easily missed because their colors blend with those of the forest floor.[25] It is more common at elevations of greater than Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value)..[16] Gomphus clavatus has been reported as forming symbiotic (mycorrhizal) associations with a variety of trees: Abies alba,[26] Abies firma,[27][28] Abies nephrolepis,[29] Abies religiosa,[30] Picea species,[31] Pinus densiflora,[27][28] Pseudotsuga menziesii,[32] and Tsuga heterophylla.[32][33] It is also reported with beech (Fagus sylvatica) in Europe.[34]
In Asia, Gomphus clavatus has been reported from China,[11] Japan,[11] Korea,[35] Malaysia,[36] Nepal,[17] and Pakistan.[11] European countries that have reported the fungus include Austria,[37] the Czech Republic,[38] France,[9] Germany,[39] Greece,[37] Italy,[37] Lithuania,[40] Poland,[41] Romania,[42] Russia,[32] Sweden,[6] Switzerland,[37] and Turkey.[43] In North America, the fungus has been found in Canada,[11] Mexico,[37] and the United States,[22] where it is abundant in the Pacific Northwest.[10]
In Europe, Gomphus clavatus appears on the national Red Lists of threatened fungi in 17 countries and is one of 33 species proposed for international conservation under the Bern Convention.[34] Due to a substantial decline in sightings,[44] Gomphus clavatus became a legally protected species in Hungary on September 1, 2005.[45] It also has legal protection in Slovakia[34] and Slovenia.[46] The species formerly occurred in England, but has not been seen since 1927 and is now regarded as extinct.[47] The fungus faces loss and degradation of its habitat; eutrophication is another potential threat.[34] Gomphus clavatus was selected as the 1998 Pilz des Jahres ("Mushroom of the Year") by the German Mycological Society, partly to highlight its vulnerable status.[48]
Edibility
Gomphus clavatus is edible (and rated as choice by some),[21][49] while others find it tasteless.[50] It has an earthy flavour and meaty texture that complements red meat dishes.[25] Like many edible fungi, consumption may cause gastrointestinal distress in susceptible individuals.[20] The flesh becomes bitter with age,[21] and older specimens may be infested with insects.[50] It has been used for cooking for some time — Fries included it in his 1867 book Sveriges ätliga och giftiga svampar (Edible and Poisonous Mushrooms in Sweden). It is highly regarded by the Zapotec people of Ixtlán de Juárez in Oaxaca,[51] and the Sherpa people in the vicinity of Sagarmatha National Park in Nepal.[17]
Extracts prepared from G. clavatus fruit bodies have a high antioxidant activity,[52] and a high concentration of phenolic and flavonoid compounds.[53] Phenolic compounds identified from the fungus include protocatechuic acid, gallic acid, gentisic acid, vanillic acid, syringic acid, cinnamic acid, caffeic acid, ferulic acid, and tannic acid.[54] In a chemical analysis of collections from the South Aegean Region of Turkey, the fungus was shown to have bioaccumulated the toxic metal cadmium to levels exceeding the maximum intake recommended by the European Union Scientific Committee on Food.[53]
References
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- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 9.0 9.1 Lua error in package.lua at line 80: module 'strict' not found. (Reprint from "Collected Mycological Papers" chronologically arranged and edited by L. Vogelenzang, Librarian Rijksherarium, Leiden, Amsterdam, vols. 1–3, 1978)
- ↑ 10.0 10.1 10.2 10.3 10.4 10.5 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 11.0 11.1 11.2 11.3 11.4 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 20.0 20.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 21.0 21.1 21.2 21.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 22.0 22.1 22.2 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 25.0 25.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Khohkryakov MK. (1956). Mycorrhizae. pp. 178–81.In: MV Gorlenki (ed.). Fungi – friends and enemies of man. Sovetskaya Nauka, Moscow.
- ↑ 27.0 27.1 Masui K. (1926). "A study of the mycorrhiza of Abies firma, S. et Z., with special reference to its mycorrhizal fungus Cantharellus floccosus, Schw". Memoirs of the College of Science. Kyoto Imperial University. Series B, vol. 2(1), Article 2, pp. 1–84.
- ↑ 28.0 28.1 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 34.0 34.1 34.2 34.3 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 37.0 37.1 37.2 37.3 37.4 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 53.0 53.1 Lua error in package.lua at line 80: module 'strict' not found.
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External links
- Gomphus clavatus in Index Fungorum
- Gomphus clavatus media at ARKive
