Agaricus xanthodermus
| Yellow Staining Mushroom - section | |
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| Scientific classification | |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Subclass: | Homobasidiomycetidae |
| Order: | Agaricales |
| Family: | Agaricaceae |
| Genus: | Agaricus |
| Species: | A. xanthodermus |
| Binomial name | |
| Agaricus xanthodermus Genev. |
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| Agaricus xanthodermus | |
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gills on hymenium |
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cap is convex |
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hymenium is free |
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stipe has a ring |
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spore print is brown |
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ecology is saprotrophic |
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edibility: poisonous |
Agaricus xanthodermus, commonly known as the yellow-staining mushroom, is a mushroom of the genus Agaricus, which displays a strong yellow colouration at the base of the stem when cut. It is poisonous for most people, causing gastrointestinal upsets but is eaten by some without apparent negative effect.
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[edit] Taxonomy
The yellow-staining mushroom was officially described in 1876. The epithet xanthodermus is derived from the Ancient Greek words for "yellow-skinned"; this is the name used by many authorities, such as Index Fungorum. However the form Agaricus xanthoderma is also often seen,[1] [2] and in fact this is more correct in classical terms; here -derma (δέρμα) is a Greek neuter noun, not an adjective which would agree in gender with Agaricus.
[edit] Description
The cap is generally 6–10 cm (2.4–4 in) in diameter, though can reach 15 cm (6 in). It is initially convex, with some young specimens having a squarish shape, though flattening with age. It is whitish, with light brown tints towards the centre. The cap is dry and smooth, but can be scaly when old. The gills of this mushroom progress from pale-pink to a chocolate color. The spore print is brown. Its white stipe is bulbous with a skirt-like ring. Microscopically, there are club-shaped cheilocystidia. The spores are 6-7×3-4 µm.
The main identifying feature is an immediate bright yellow colouration on cutting through the base of the stem, or scraping the flesh; later the affected area fades to a dull brown. Numerous edible Agaricus species, such as A. augustus, A. arvensis and A. silvicola, turn yellow to a greater or lesser extent, but they do not display such an intense reaction.
Agaricus xanthodermus has an unpleasant characteristic smell, which is phenolic, that is reminiscent of ink or carbolic soap. The smell is especially strong at the base of the stem. On cooking the smell becomes very noticeable, and this may deter people from eating it inadvertently.
[edit] Distribution and habitat
This mushroom is very common and widely distributed in North America, Europe, West Asia including eastern Anatolia [3] and Iran [4], North Africa [1], and southern Africa [5]. It has been introduced into Australia. It occurs in woods, lawns, gardens and hedgerows in autumn. This is a saprobic species.
[edit] Related species
A. xanthodermus belongs to a group of related species (the "Xanthodermatei") which likewise discolour bright yellow and have a phenolic smell. They include A. praeclaresquamosus (formerly A. placomyces) which has dark grey scales, and A. pilatianus which does not have a bulbous stem.[1]
[edit] See also
[edit] References
- ^ a b c Courtecuisse, R. & Duhem, B. (1994) "Guide des champignons de France et d'Europe" Delachaux et Niestlé ISBN 2-603-00953-2, also available in English
- ^ Meinhard Moser, translated by Simon Plant: Keys to Agarics and Boleti (Roger Phillips 1983) ISBN 0-9508486-0-3
- ^ Demirel K, Uzun Y, Kaya A (2004). "Some Poisonous Fungi of East Anatolia" (PDF). Turk J Bot 28: 215–19. http://journals.tubitak.gov.tr/botany/issues/bot-04-28-1-2/bot-28-1-2-23-0207-2.pdf. Retrieved 2008-02-08.
- ^ Asef Shayan, M.R. (2010) (in Persian). قارچهای سمی ایران (Qarch-ha-ye Sammi-ye Iran) [Poisonous mushrooms of Iran]. Iran shenasi. p. 214. ISBN 978-964-2725-29-8.
- ^ Van der Westhuizen, GCA and Eicker, A (1994) Mushrooms of Southern Africa, Field Guide. Struik Publishers, Cape Town
- Collins Gem Guide: Mushrooms and Toadstools, Stefan Buckzacki (1982).
[edit] External links
- “Agaricus xanthodermus” by Robert Sasata, Healing-Mushrooms.net, November, 2007.
