Ivory snail

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Ivory snail
Hygrophorus eburneus-pastorino.JPG

Ivory snail ( Hygrophorus eburneus )

Systematics
Class : Agaricomycetes
Subclass : Agaricomycetidae
Order : Mushroom-like (Agaricales)
Family : Snail relatives (Hygrophoraceae)
Genre : Snail ( hygrophorus )
Type : Ivory snail
Scientific name
Hygrophorus eburneus
( Bull  .: Fr. ) Fr.

The ivory snail ( Hygrophorus eburneus , Syn. Agaricus eburneus Bull. , Gymnopus eburneus [Bull.] Gray , Limacium eburneum [Bull.] P. Kumm. ) Is an edible fruiting mushroom from the family of snail relatives (Hygrophoraceae). It is widespread in Europe and North America and has also been collected in North Africa. The fruit bodies are medium-sized, pure white and, when moist, covered with a layer of mucus that is thick enough to make it difficult to collect. The lamellas are wide or grown down on the stem. As the English-language name "ivory waxy cap" suggests, they feel waxy when rubbed between the fingers. Like all Hygrophorus species, it lives in a symbiotic mycorrhizal connection (exchange of nutrients) with trees. It is common in a variety of forest types where the fruiting bodies grow on the ground. The ivory snail is the type species of the genus of the snail. A number of biologically active chemicals have been extracted from the fruit bodies, including fatty acids with bactericidal and fungicidal properties. It is fruitful in Central Europe between September and November.

features

Macroscopic features

The species is characterized by its extremely slimy hat.

The ivory snail's hat is two to seven centimeters tall with a shape from convex to flattened, sometimes with a hump. In old age, the edge of the hat sometimes rises and the middle of the hat is depressed. The hat is pure white and can be slimy to sticky depending on the ambient humidity. The surface of the hat is smooth, the edge is flat and, in young specimens, is curled up and covered with short fibers. The flesh is white, thick in the middle of the hat and tapering towards the edge of the hat. The smell and taste are mild.

The lamellae are somewhat curved downwards, i.e. curved upwards towards the stem and then run down the stem for a short distance. In terms of distance, they are distant or almost distant, so that an intermediate distance is visible. The lamellae are moderately wide, widest near the stem, narrower in front, pure white, slightly yellowish or brownish yellow with age or dried. The blade edges are smooth.

The stem is slimy, 4.5 to 15 centimeters long, 2 to 8 millimeters thick, evenly strong over the entire length down to the bottom, slightly tapering with a very thinned base. The surface is silky under the slime. The upper end of the stem is covered with short, pure white fibrils that sometimes turn gray or dirty with age. It is initially filled with cotton-like mycelium tissue and later becomes hollow.

The hats of dried fruiting bodies typically stay white while the stems darken, especially if they are initially soaked in water.

Microscopic features

The spores are ellipsoidal and smooth.

The spores appear white when viewed en masse, like a spore print . A light microscope reveals further details: the spores are ellipsoidal, smooth and measure 6 to 8 by 3.5 to 5 micrometers. They are pale yellow in Melzer's reagent . The basidia (spore-bearing cells) are 42 to 52 by 6 to 8 micrometers and four-pore. There is no pleuro Zystiden or cheilocystidia. The lamellar tissue consists of branched hyphae about 7 to 12 micrometers wide. The cap skin consists of gelatinous, narrow (3 to 6 micrometers) hyphae tissue, the threads of which are creeping (stooped), but typically with some upright free ends. Buckle connections are present in the hyphal tissue .

Species delimitation

A species that looks similar to the ivory snail is the spruce snail ( Hygrophorus piceae ), which differs through a less slimy hat, a dry to slightly sticky stem and frequent company with spruce trees. The slimy- ringed snail ( Hygrophorus gliocyclus ) is just as slimy, but has a cream-colored hat, thicker stem and grows with pines. Hygrophorus borealis is also similar in appearance, but has a smaller hat diameter of up to 4.5 centimeters and is not slimy. The oak snail ( Hygrophorus cossus ), which typically grows with oaks, differs from hat and lamellae by pale pink-yellow-brown color and has a distinct sour odor; Nor does Hygrophorus cossus show any reaction with potassium hydroxide on the stalk, as does the ivory snail. The shiny mucous umbrella ( Limacella illinita ) has lamellae that are not waxy and not attached to the stem.

Habitat and Distribution

The fruiting bodies of the ivory snail prefer to grow on (moderately) moist, loamy and calcareous soil. In Europe it can often be found in mixed deciduous forests from August to November.

The mushroom is also widespread in North America and is also found in Israel and North Africa.

Taxonomy and systematics

The species was first in 1783 by the French botanist Jean Bulliard as Agaricus eburneus named. Elias Fries divided the large genus Agaricus in his Systema Mycologicum I into a number of tribe and classified Agaricus eburneus in the tribe Limacium . When Fries first defined the genus Hygrophorus in his Epicrisis Systematis Mycologici in 1836 , he included Hygrophorus eburneus there. The mushroom was also named Limacium eburneum by Paul Kummer in 1871 when he raised Fries' tribe to the rank of genera, and by Samuel Frederick Gray in 1821 as Gymnopus eburneus .

The type epithet “eburneus” is a Latin adjective meaning “like ivory” or “ivory colored”.

Inquiry systematics

The ivory snail is the type species of the genus Hygrophorus and is classified in the section Hygrophorus , subsection Hygrophorus . This includes species with non- amyloid , smooth spores and diverging hyphae in the tissue of the hymenium . Other species in this subsection are the non- discoloring snail ( Hygrophorus coccus ), the weighty snail ( Hygrophorus ponderatus ), the discoloring snail ( Hygrophorus discoxanthus ), and Hygrophorus glutinosus and Hygrophorus eburneiformis, two North American species. Other authors put him in the Eburnei section . This section includes species that have a more or less greasy to slimy hat and stem. The hat is whitish to cream, pink-ocher or pale orange in color.

meaning

edibility

The mushroom is edible, although it may not appeal to many because of its sliminess. In China, a yak milk drink is made with ivory snails and yak milk, in lactic acid fermentation with Lactobacillus delbrueckii subsp. bulgaricus , Streptococcus thermophilus and Lactobacillus acidophilus as a mixed starter culture.

Bioactive compounds

γ-Oxocrotonic acids from Hygrophorus eburneus

Several biologically active fatty acids with bactericidal and fungicidal properties have been isolated from the fruiting bodies of the ivory snail and identified. The biologically active fatty acids are based on a chemical structure called γ-oxocrotonate. The following gamma-Oxocrotonat derivatives were found in the fungus: (2 E , 9 E ) -4-oxooctadeca-2,9,17-trienoic acid; (2 E , 11 Z ) -4-oxooctadeca-2.11, 17-trienoic acid, ( E ) -4-oxohexadeca-2,15-dienoic acid, ( E ) -4-oxooctadeca-2,17-dienoic acid, (2 E , 9 E ) -4-oxooctadeca-2.9 -dienoic acid, (2 E , 11 Z ) -4-oxooctadeca-2,11-dienoic acid, ( E ) -4-oxohexadec-2-enoic acid and ( E ) -4-oxooctadec-2-enoic acid. The compound ( E ) -4-oxohexadec-2-enoic acid was investigated for potential use as a fungicide against the egg fungal species Phytophthora infestans , a pathogen that causes late blight in potatoes and late blight in tomatoes.

Additional secondary metabolites discovered in the ivory snail include the ceramide compound called hygrophamide ((2 S , 3 R , 4 R , 2 ' R ) -2- (2'-hydroxy-9' Z -ene-tetracosanoylamino) -octadecane-1 , 3,4-triol), and those known as norharman Harman and β-carboline - alkaloids . The 2008 discovery report on the latter two compounds represents the first known occurrence in mushroom fruit bodies.

Web links

Commons : Ivory Snail ( Hygrophorus eburneus )  - Collection of images, videos, and audio files

Individual evidence

  1. ↑ Hygrophorus eburneus (Bull.) Fr. In: Index Fungorum. Center for Agricultural Bioscience International, accessed August 25, 2010 .
  2. ^ A b Alexander Hanchett Smith: North American species of Mycena . University of Michigan Press, Ann Arbor, Michigan 1947, pp. 253-255 (English, umich.edu ).
  3. ↑ a b Lexemuel Ray Hesler, Alexander Hanchett Smith: North American species of Hygrophorus . 1st edition. University of Tennessee Press, Knoxville TE 1963, p. 248 (English, umich.edu ).
  4. ^ David Arora: All that the Rain Promises and More. A Hip Pocket Guide to Western Mushrooms . In: Ten Speed ​​Press . Berkeley, California 1991, ISBN 0-89815-388-3 , pp. 47 (English).
  5. ↑ a b William C. Roody: Mushrooms of West Virginia and the Central Appalachians . The University Press of Kentucky, Lexington, Kentucky 2003, ISBN 0-8131-9039-8 , pp. 119, 250 (English).
  6. ↑ Hope H. Miller, Orson K. Miller Jr .: North American mushrooms. A field guide to edible and inedible fungi . 1st edition. Falcon Guides Press Publishing, Guilford, Connecticut, USA 2006, ISBN 0-7627-3109-5 , pp. 69 (English).
  7. ↑ Cornelis Bas, Thomas W. Kuyper, Machiel Evert Noordeloos, Else C. Vellinga: Flora Agaricina Neerlandica . Ed .: Cornelis Bas. tape 3 . CRC Press, Boca Raton, Florida 1990, ISBN 978-90-6191-971-1 , pp. 118-119 (English).
  8. ↑ Hans E. Laux: The great cosmos mushroom guide. All edible mushrooms with their poisonous doppelgangers Franckh-Kosmos Verlag, Stuttgart, 2001, ISBN 3-440-08457-4 .
  9. ↑ N. Binyamin, Z. Avizohar: Species of Hygrophorus in Israel . In: Israel Journal of Botany . tape 22 , no. 4 , 1973, p. 258-262 .
  10. ^ R. Maire: New fungi from North Africa . In: Bulletin trimestriel de la Societe mycologique de France . tape 44 , no. 1 , 1928, pp. 37-56 .
  11. ^ Jean Baptiste François Bulliard: Herbier de la France . tape 3 , 1783, p. 97-144 (French).
  12. ↑ Elias Magnus Fries: Systema Mycologicum . tape 1 . ex officina Berlingiana, 1821, p. 16 (Latin, archive.org [accessed June 30, 2010]).
  13. ^ Elias Magnus Fries: Anteckningar öfver de i Sverige växande ätliga Svampar . Palmblad, Sebell & C., Upsala 1836, pp. 45 (Swedish, archive.org ).
  14. ↑ Paul Kummer: The guide to mushroom science. Instructions for the methodical, easy and secure identification of the fungi occurring in Germany, with the exception of mold and all too tiny slime and core fungi . 1st edition. Verlag von E. Luppe's Buchhandlung, Zerbst 1871, p. 119 ( archive.org ).
  15. ^ Samuel Frederick Gray: A Natural Arrangement of British Plants. According to their relations to each other as pointed out by Jussieu, De Candolle, Brown, & c. tape 1 . Baldwin, Cradock, and Joy, London 1821, pp. 610 (English, archive.org ).
  16. ↑ eburneus in the Wiktionary
  17. ↑ David H. Headrick, Gordon Gordh: A Dictionary of Entomology . Center for Agricultural Bioscience International Publishing, Wallingford, Oxfordshire, England 2001, ISBN 0-85199-655-8 , pp. 301 (English).
  18. ↑ Marcel Bon (ed.): Parey's book of mushrooms . Franckh-Kosmos Verlag, Stuttgart 2005, ISBN 3-440-09970-9 , pp. 114 .
  19. ↑ David Arora, Mushrooms Demystified: a Comprehensive Guide to the Fleshy Fungi . Ed .: Ten Speed ​​Press. Berkeley, California 1986, ISBN 0-89815-169-4 , pp. 119-120 (English).
  20. ↑ Jiang-ping Fang, Zheng-chang Zhong: Study on Hygrophorus eburnus - yak milk beverage . In: China Dairy Industry . tape 37 , no. 6 , 2009, ISSN  1001-2230 , p. 62-64 (Chinese).
  21. ^ Axel Teichert, Tilo Lübken, Jürgen Schmidt, Andrea Porzel, Norbert Arnold, Ludger Wessjohann: Unusual Bioactive 4-Oxo-2-alkenoic Fatty Acids from Hygrophorus eburneus . In: Journal of Nature Research B . 60, 2005, pp. 25–32 ( PDF , free full text).
  22. ↑ Lennart Eschen-Lippold, Tobias Draeger, Axel Teichert, Ludger Wessjohann, Bernhard Westermann, Sabine Rosahl, Norbert Arnold: Antioomycete Activity of γ-Oxocrotonate Fatty Acids against P. infestans . In: Journal of Agricultural and Food Chemistry . tape 57 , no. 20 , October 28, 2009, p. 9607-9612 , doi : 10.1021 / jf902067k , PMID 19778058 (English).
  23. ↑ Yan Qua, Hong-Bin Zhang, Ji-Kai Liu: Isolation and Structure of a New Ceramide from the Basidiomycete Hygrophorus eburnesus . In: Journal of Nature Research B . 59, 2004, pp. 241–244 ( PDF , free full text).
  24. ↑ Axel Teichert, Tilo Lübken, Jürgen Schmidt, Christine Kuhnt, Manfred Huth, Andrea Porzel, Ludger Wessjohann, Norbert Arnold: Determination of β-carboline alkaloids in fruiting bodies of Hygrophorus spp by liquid chromatography / electrospray ionization tandem mass spectrometry . In: Phytochemical Analysis . tape 19 , no. 4 , July 19, 2008, p. 335-341 , doi : 10.1002 / pca.1057 , PMID 18401852 (English).