amanita

Amanita
Amanita muscaria Albin Schmalfuß, 1897
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Subclass:	Hymenomycetes
Order:	Agaricales
Family:	Amanitaceae
Genus:	Amanita Pers.
Type species
Amanita muscaria
Diversity
c.600 species
Synonyms
Aspidella

The genus Amanita contains about 600 species of agarics including some of the most toxic known mushrooms found worldwide. This genus is responsible for approximately 95% of the fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own. The most potent toxin present in these mushrooms is α-amanitin.

The genus also contains many edible mushrooms, but mycologists generally discourage amateur mushroom hunters from selecting these for human consumption. Nonetheless, in some cultures, the larger local edible species of Amanita are mainstays of the markets in the local growing season. Samples of this are Amanita zambiana and other fleshy species in central Africa, A. basii and similar species in Mexico, A. caesarea in Europe, and A. chepangiana in South-East Asia. Other species are used for colouring sauces, such as the red A. jacksonii with a range from eastern Canada to eastern Mexico.

Many species are of unknown edibility, especially in countries such as Australia where many fungi are little-known. Understandably, this is not a genus that lends itself to safe experimentation.

Taxonomy

The name is possibly derived from Amanon, a mountain in Cilicia.

A first incarnation from Tentamen dispositionis methodicae Fungorum 65. 1797 is cited as devalidated: "Introduced to cover three groups already previously distinguished by Christian Hendrik Persoon (in [...] Tent. 18. 1797) under Agaricus L., but at that time not named. It is worth stressing that the species now known as Amanita caesarea was not mentioned."

With Agaricus L. in use, Amanita was a nomen nudum per modern standard, so Persoon gave it a new life unrelated to its previous incarnations, and that is finally published after a starting date by Hooker (the citation is Pers. per Hook., 1821). He reuses Withering's 1801 definition (A botanical arrangement of British plants, 4th ed.). "The name Amanita has been considered validly published on different occasions, depending on various considerations." Proposed types include (given as Amanita. Sometimes they were selected as Agarici):

• A. livida Pers. (By Earle, in 1909). Had been excluded in Vaginata or Amanitopsis and could not be chosen.
• A. muscaria Pers. (By Clemens & Shear, 1931) for the genus (1801) from Synopsis fungorum, was generally transferred to the one from Hooker's Flora of Scotland, which is currently considered the valid publication of Amanita (or was in the 50s).
• A. phalloides (by Singer, 1936) for the 1801 genus.
• A. bulbosa (by Singer & Smith, 1946) for Gray's republication. This is incorrect as Gray's A. bulbosa is a synonym of A. citrina. Some authors consider Gray to be the first valid republisher.
• A. caesarea (by Gilbert, 1940). Troublesome because not known personally to Persoon or Fries.

Donk concludes the earliest valid type is A. muscaria, the species in Hooker, adding that he'd personally favor A. citrina.

The name has been republished three times in 1821: in Hooker, Roques and Gray (in that order). Roques maintained Persoon's circumscription, including Amanitopsis and Volvaria. Gray excluded Amanitopsis and Volvariella into Vaginata. Right after, Fries reset the name by reducing the genus to a tribe of Agaricus, minus pink-spored Volvariella. This tribe became a subgenus, than genus via various authors, Quélet, although not the first, often being attributed the change. Sometimes it was used in a Persoonian sense (whether that is a correct use according to ICBN is not clear).

Homonyms of Amanita Pers. are Amanita adans. (1763, devalidated) and Amanita (Dill) Rafin. (1830)

Toxicity

Amanita caesarea (edible)

Several members of the section Phalloidieae are notable for their toxicity, containing toxins known as amatoxins which can cause liver failure and death. These include the death cap A. phalloides, species known as destroying angels including A. virosa, A. bisporigera and A. ocreata and the fool's mushroom A. verna.

More recently, a series in the subgenus Lepidella have been found to cause acute renal failure, including A. smithiana of Northwestern North America, A. pseudoporphyria of Japan, and A. proxima of southern Europe.^[1]

See also

Fungi portal

• Destroying angel
• List of Amanita species

References

• Donk, M.A. (1962). "The generic names proposed for Agaricaceae". Beiheifte zur Nova Hedwigia 5: 1–320. ISSN 0078-2238. 

External links

Wikimedia Commons has media related to: Amanita

• The Genus Amanita - AmericanMushrooms.com.
• Rodham E. Tuloss and Zhu-liang Yang's Amanita site – Comprehensive listing of the nearly 600 named Amanita species with photos and/or technical details on over 510 species.
• "The genus Amanita" by Michael Kuo, MushroomExpert.Com, March 2005.