Discoloring snail

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Discoloring snail
Hygrophorus discoxanthus 151018w.JPG

Discoloring snail ( Hygrophorus discoxanthus )

Systematics
Class : Agaricomycetes
Subclass : Agaricomycetidae
Order : Mushroom-like (Agaricales)
Family : Snail relatives (Hygrophoraceae)
Genre : Snail ( hygrophorus )
Type : Discoloring snail
Scientific name
Hygrophorus discoxanthus
( Abbreviation Fr.) Rea

The discoloring Schneck Ling ( Hygrophorus discoxanthus , syn. Hygrophorus chrysaspis Métrod , Hygrophorus cossus sensu Bres, Neuhoff, Bresinsky;. Limacium melizeum sensu crocheted) is a agaric from the family of Schneck Ling relatives (Hygrophoraceae). He has a greasy to slimy hat that is whitish when young, but turns increasingly yellow-brown to rust-brown with age. The initially whitish lamellae also turn yellow-brown later. The ringless stem is moist and greasy to slimy below the tip of the stem. The meat of the snail that gets mixed with KOHimmediately discolored rust-brown, has an unpleasant, aromatic-sour odor. The mycorrhizal fungus, which is widespread in Europe, is associated with beeches. The fruiting bodies appear between August and October. The mushroom, also known as yellow-discolouring snail or browning snail , is considered inedible, but some authors describe it as conditionally edible.

features

Macroscopic features

The hat is 3-5 (-8) cm wide and when young, hemispherical to conical, then arched and later flattened. The middle of the hat is often depressed. The hat is colored white to creamy white when young, but soon turns yellow-brown to rust-brown from the initially curved edge. Dried fruit bodies are rust-brown or red-brown to almost blackish. In damp weather, the hat surface is clearly greasy to slimy, dry it can also be quite matt. The edge of the hat is sharp and can protrude slightly beyond the lamellas.

The lamellas have grown wide on the stem or run down a little. As is typical for snails, they are quite distant (with 32-40 continuous lamellae, with 1-3 intermediate lamellae in between ). The lamellae, which are up to 6 mm wide, are initially creamy-white and increasingly turn yellow-brown. The spore powder is white.

The young whitish stalk is 3-6 (-10) cm long and 0.5-1 cm wide. It is more or less cylindrical and clearly moist and greasy below the tip. Like hat and lamellas, it also changes color with age. The tip of the handle is finely flaky or moistened with droplets. Towards the base, the stalk is more or less pointed and with old fruiting bodies it is mostly hollow.

The rather soft meat is white and has an unpleasant odor that sticks to the fingers for a long time. The taste is also unpleasant. With KOH, the whole fruiting body (and not just the tip of the stem) immediately turns reddish brown.

Microscopic features

The inamyloid spores are more or less elliptical to oval, smooth and translucent and measure (6.5) 7.0–9 × 4.5–6 µm. The average Q value (quotient of spore length and width) is between 1.5 and 1.7. The narrow to narrow-clubbed basidia are 34–50 µm long and 6.5–8 µm wide (Q value = 4.5–7.5). They are usually 4-spore. The hymenophoral trama is bilateral and consists of cylindrical to inflated hyphae (60–140 × 4.5–25 µm). The Pileipellis (hat skin) is an up to 300 µm thick ixotrichoderm , which consists of rather compact, erect and interwoven, hyaline, 2.5-5 µm wide hyphae. The numerous free ends are clipped at the tip and there about 4.5–6.5 µm wide. The stipitipellis (stem bark) is a fairly thin (about 120 µm thick) Ixocutis or an Ixotrichoderm. The hyphae are about 4–6 µm wide. The apical ends of the hyphae are tapered or slightly clubbed. Buckles are very common throughout the fruiting body.

Species delimitation

The discoloring snail is characterized by its striking smell, the discoloration that occurs with age and its location (growing in beeches). However, it can be confused with a number of white-capped snails. Three snails, which also have a greasy to slimy hat and stem, are particularly similar. The most common doppelganger is the ivory snail ( H. eburneus ) , which also grows in the beech forest . Its fruiting bodies do not discolour with age and the base of the stem turns orange to orange-brown with KOH. The oak snail ( H. cossus ) grows in oaks and hardly changes color with KOH, while the lamellae of the birch snail ( H. hedrychii ) have a distinctly reddish tint.

Ecology and diffusion

European countries with evidence of finding of the discoloring snail.
Legend:
  • Countries with found reports
  • Countries without evidence
  • no data
  • non-European countries

    • The discoloring snail is widespread in Europe and is likely to occur in the entire distribution area of ​​the common beech. It is absent on the Irish island, in Great Britain (island) it is mainly common in the south, in Scotland it is very rare and completely absent in the north. The snail is also rare in the Netherlands. But it is quite common in neighboring Belgium and Germany, at least in limestone areas. In southern Europe it is widespread from Spain to Bulgaria. In Greece, only the closely related Hygrophorus cossus (oak snail) was found in beech forests. There may be a mix-up (or incorrect naming) here, as the oak snail is tied to oak. However, the epithet cossus was wrongly used for the discoloring snail H. discoxanthus for a long time . In northern Europe the snail occurs only in the south. It is missing in Finland, but there is evidence from Estonia and Lithuania. It has even been proven in Russia. Its occurrence here is likely to be limited to the Caucasus region. In Germany, Austria and Switzerland, it is quite common, mainly on calcareous soils. It is absent in high montane and alpine locations in the Alps. The highest site in Switzerland is 1540 m and in Austria 1300 m above sea level.

    The fruiting bodies of the mycorrhizal fungus appear solitary or gregarious from August to October. The discoloring snail is a strict companion of the beech. It prefers calcareous, loamy soils.

    Systematics

    In terms of nomenclature, the white snails from the Eburneus group were for a long time an extremely confused group in which one type of mushroom could have different names depending on the author, but where one name was also used for different types of mushroom. As a typical representative of this group, the discoloring snail had to change its name several times over the past 100 years. On the one hand, this was due to the fact that the species descriptions in the older, mycological literature are often inadequate by today's standards, and on the other hand, because the species diagnoses in Friese's works often change more or less, as Fries revised or clarified his view over the years .

    In his Observationes Mycologicae in 1815 E. Fries described a whitish snail with a slimy hat, the middle of the hat is yellow and the broad, sloping lamellas increasingly turn brown. He named this mushroom Agaricus discoxanthus . In his Systema Mycologicum (1821), however, Fries only mentioned this name as forma (b) under Agaricus eburneus , together with Agaricus nitens With. , (actually A. nitens Schaeff. (1774)) and A. cossus Sowerby . At the time, he was no longer sure whether the taxon described six years earlier really embodied a species in its own right. In his Epicrisis systematis mycologici (1838) and in later publications Fries changed his mind again. He was now of the opinion that A. discoxanthus was a synonym for Hygrophorus cossus .

    But even if Fries described the discoloring snail in his Observationes Mycologicae (which is by no means certain), this is not the oldest scientific description and name of the discoloring snail. Already in 1774 Jacob Chr. Schäffer had described a white snail from the Eburneus group with Agaricus nitens Schäffer . However, his drawing and his description of the species are not detailed enough to be able to say for sure which species he described exactly. 23 years later, J. Sowerby described and drew a white snail, which is undoubtedly the discolouring snail. Sowerby believed he recognized Schaeffer's Agaricus nitens in it and therefore gave his snail this name. But although Schäffer's name is clearly older (1774) than that of Fries (1815), Schäffer's name can not be used for taxonomic reasons, as it is an illegitimate homonym of the sanctioned name Agaricus nitens Batsch (1789).

    In 1918 Adalbert Ricken described the discoloring snail under the name Limacium melizeum , because he believed he recognized Frieses Hygrophorus melizeus in it. Today Hygrophorus melizeus is mostly interpreted in the sense of Carleton Rea and synonymous with Hygrophorus hedrychii . The generic name Limacium (Fr. ex Rabenh.) P. Kumm. was introduced by Paul Kummer in 1871 , but is no longer used today. The Italian mycologist G. Bresadola, on the other hand, used the name Hygrophorus cossus (Sowerby) Fr. in his description in 1928 . His interpretation of the name is essentially based on the description of H. cossus in Frieses Monographia (1851).

    When the French mycologist Georges Métrod described the discoloring snail in 1938, he avoided choosing a Frisian name, but instead gave it a completely new name, Hygrophorus chrysaspis Métrod , which became established in the following years at least in German and French-speaking countries. Until Walter Neuhoff in 1962 and Bresinsky in 1965 suggested replacing H. chrysaspis with the older, Frisian name Hygrophorus cossus . At the latest when MM Moser 1983 this name in his determination work "Röhrlinge-Blätterpilze, 5th ed." took over, this name prevailed until the Dutch mycologist E. Arnolds in 1986 dealt with the taxonomic and nomenclature problems of the genus Hygrophorus . Arnold was of the opinion that the name Hygrophorus cossus could not be used for the discoloring snail, even if Fries used it in this sense (at least in later works). Much more important is how the original author, J. Sowerby, understood the species. Since Sowerby described the discoloring snail under the name Agaricus nitens , A. coccus must be a different taxon. He suggested using the long-forgotten name Hygrophorus discoxanthus (Fr.) Rea , which Fries had introduced in 1815 and which had been recombined by Carleton Rea in 1908 , instead .

    His suspicion was confirmed 18 years later. Fortunately, original material from Agaricus cossus , which Sowerby himself collected in 1794 , is still kept in the Herbarium of the Royal Botanic Gardens (Kew) . In 2004, Ellen Larsson and Stig Jacobsson succeeded in sequencing the ITS region. Surprisingly, sequence analyzes showed that Sowerby's Agaricus cossus is identical to the type of H. quercetorum ( oak snail ). Since H. cossus is the older name, it has since replaced the name introduced by PD Orton in 1985.

    meaning

    The snail is considered edible to a limited extent, at least those specimens in which the smell is less developed. According to Laux, the mutable snail is not an edible mushroom.

    swell

    Individual evidence

    1. ↑ a b Hans E. Laux, Andreas Gminder : The great cosmos mushroom guide. All edible mushrooms with their poisonous doppelgangers. Franckh-Kosmos, Stuttgart 2015, ISBN 978-3-440-14530-2 , p. 100.
    2. ↑ a b Arnolds, E .: Flora Agaricina Neerlandica . Ed .: C. Bas, Th. Kuyper, ME Noordeloos, ME & EC Vellinga. tape 2 . Rotterdam 1990, Tribus Hygrophoreae, p. 115–133 ( limited preview in Google Book search).
    3. ↑ Ewald Gerhardt: Mushrooms. Volume 1: Lamellar mushrooms, pigeons, milklings and other groups with lamellas (=  spectrum of nature / BLV intensive guide ). BLV, Munich / Vienna / Zurich 1984, ISBN 3-405-12927-3 , p. 43 .
    4. ↑ Andreas Bresinsky: Demarcation of some types of the sparkling wine. Hygrophorus Genus Hygrophorus (Agaricales) and their occurrence in Sweden . In: Journal of Mushroom Science . tape 31 , 1965, p. 1–6 ( DGfM article archive ).
    5. ^ Database of mushrooms in Austria. In: austria.mykodata.net. Austrian Mycological Society, accessed December 3, 2016 .
    6. ↑ Basidiomycota Checklist-Online - Hygrophorus discoxanthus. In: basidiochecklist.info. Retrieved December 3, 2016 .
    7. ↑ Cvetomir M. Denchev & Boris Assyov: Checklist of the larger basidiomycetes in Bulgaria . In: Mycotaxon . tape 111 , 2010, ISSN  0093-4666 , p. 279–282 ( online [PDF]).
    8. ↑ Belgian List 2012 - Hygrophorus discoxanthus. Retrieved December 3, 2016 .
    9. ↑ Worldwide distribution of Hygrophorus discoxanthus. In: GBIF Portal / data.gbif.org. Retrieved December 3, 2016 .
    10. ^ DM Dimou, GI Zervakis & E. Polemis: Mycodiversity studies in selected ecosystems of Greece: I. Macrofungi from the southernmost Fagus forest in the Balkans (Oxya Mountain, central Greece). In: [Mycotaxon] . Vol: 82, 2002, pp. 177-205 (English, cybertruffle.org.uk ). cybertruffle.org.uk ( Memento of the original from September 24, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.cybertruffle.org.uk
    11. ↑ Ilkka Kytövuori et al .: Chapter 5.2, Distribution table of agarics and boletes in Finland . 2005, ISBN 952-11-1997-7 , pp. 105–225 ( helsinki.fi [PDF] Original title: Helttasienten ja tattien levinneisyystaulukko .).
    12. ↑ Jean-Pierre Prongué, Rudolf Wiederin, Brigitte Wolf: The fungi of the Principality of Liechtenstein . In: Natural history research in the Principality of Liechtenstein . Vol. 21. Vaduz 2004 ( online [PDF]). online ( Memento of the original from November 15, 2011 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.llv.li
    13. ↑ Grid map of Hygrophorus discoxanthus. In: NBN Gateway / data.nbn.org.uk. Retrieved December 3, 2016 .
    14. ^ Hygrophorus discoxanthus. Pilzoek database, accessed December 3, 2016 .
    15. ↑ NMV Verspreidingsatlas online: Hygrophorus discoxanthus. In: verspreidingsatlas.nl. Retrieved December 3, 2016 .
    16. ↑ Distribution atlas of mushrooms in Switzerland. (No longer available online.) In: wsl.ch. Federal Research Institute for Forests, Snow and Landscape WSL, archived from the original on October 15, 2012 ; Retrieved December 3, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.wsl.ch
    17. ^ Elias Magnus Fries: Observationes Mycologicae . Ed .: sumptibus G. Bonnieri [Hauniae]. Vol. 1, 1815, pp. 15 (Latin, cybertruffle.org.uk ).
    18. ↑ Elias Magnus Fries: Systema Mycologicum . Volume I. Ex Officina Berlingiana., Lund & Greifswald 1821, p. 33 (Latin, cybertruffle.org.uk ).
    19. ^ Elias Magnus Fries: Epicrisis systematis mycologici . seu synopsis hymenomycetum. Typographia Academica, Upsala 1838, p. 321 (Latin, cybertruffle.org.uk ).
    20. ^ Jacob Christian Schäffer: Fungorum qui in Bavaria et Palatinatu circa Ratisbonam nascuntur icones; Tomus tertius . Typis Keizerianis, Ratisbonae (Regensburg) 1771 ( description illustration ).
    21. ↑ James Sowerby ,: Colored figures of English fungi or mushrooms . Ed .: J. Davis. London 1797 (English, illustration description ).
    22. ^ Giacomo Bresadola: Iconographia Mycologica. Ed .: Gruppo Micologico "G. Bresadola". Vol. XII, 1928, pp. 304 (Latin, online ).
    23. ↑ Walter Neuhoff: Confused white snails around Hygrophorus eburneus . In: Westphalian mushroom letters . tape 3 , 1962, pp. 59–64 ( online [PDF]).
    24. ^ AL Smith and C. Rea: New and rare British fungi . In: Transactions of the British Mycological Society . tape 3 , no. 1 , 1908, p. 34-46 ( cyberliber ).
    25. ^ E. Arnolds ,: Notes on Hygrophoraceae - VII . In: Persoonia . tape 13 , 1986, pp. 69-76 ( naturalis.nl ).
    26. ↑ Ellen Larsson and Stig Jacobsson: Controversy over Hygrophorus cossus settled using ITS sequence data from 200 year-old type material . In: Mycological Research . tape 108 , no. 07 , 2004, p. 781-786 ( pdf ).

    Web links

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