False morel

From Free net encyclopedia

{{Taxobox | color = lightblue | name = False Morel | image = FalseMorel.jpeg | regnum = Fungi | phylum = Ascomycota | classis = Ascomycetes | ordo = Pezizales | familia = Helvellaceae | genus = Gyromitra | species = G. esculenta | binomial = Gyromitra esculenta | binomial_authority = (Pers. ex Pers.) Fr. }}

The false morel (Gyromitra esculenta), colloquially known as "red mushroom" or "beefsteak mushroom", is a poisonous ascomycete fungus somewhat similar in appearance to the "true" morel (Morchella sp.). While false morels are deadly poisonous when raw, in some parts of the world they are considered edible (and delicious) if properly parboiled.

False morels contain gyromitrin, a volatile water-soluble hydrazine compound that acts as a hemolytic toxin as well as damaging the liver and the central nervous system. Due to its volatility, even the mere presence of fresh false morels in a poorly ventilated space may cause gyromitrin poisoning symptoms such as headache, dizziness and nausea. Consuming raw or incorrectly prepared false morels can result in catastrophic liver failure and death.

To render false morels edible most of the gyromitrin must be removed. The recommended procedure involves cutting the mushrooms into small pieces and boiling them twice in copious water (at least 3 parts water to one part chopped mushrooms) for at least five minutes. The gyromitrin will dissolve in the water, which must be discarded after each boiling. Some of the gyromitrin will also evaporate, producing toxic fumes. If boiling the mushrooms indoors, one should therefore take care to ensure adequate ventilation, and, if symptoms of gyromitrin poisoning appear, immediately seek fresh air.

Even after boiling, small amounts of gyromitrin remain in the mushrooms. While these small quantities will not cause noticeable symptoms to most people, some people may be hypersensitive to the toxin, and can become seriously ill from eating even properly prepared false morels. Gyromitrin sensitivity is apparently not a hereditary matter, further confusing the question of toxicity. Some sources claim false morel toxicity to be purely a matter of luck and/or individual variation, but these often fail to make a distinction between raw and prepared mushrooms, or cite incorrect methods of preparation.

There is also evidence that even small amounts of gyromitrin may have a cumulative carcinogenic effect. Thus it may not be advisable to consume even properly treated false morels too frequently, and many sources advise completely against consuming false morels at all.

Afficionados of false morels describe them as one of the choicest of all culinary mushrooms. They are popular in Finland and Scandinavia, where they are sold commercially (after treatment to remove most of the toxin), and the upper Great Lakes region of North America. In Finland false morels may even be sold fresh, but must always be accompanied by conspicuous warning signs as well as instructions on how to prepare them correctly. Only four cases of fatal gyromitrin poisoning have been recorded in Finland between 1885 and 1988, all of them caused by eating the mushrooms raw.

While false morels somewhat resemble "true" morels, in that both are brown and wrinkly, the two are quite easily distinguished with some practice. False morels are irregularly shaped, resembling a brown brain, while the true morel is more symmetric and looks more like a pitted gray, tan, or brown sponge. False morels also generally have solid stems, whereas true morels are hollow.

The name false morel is also applied to other species of the genus Gyromitra, such as G. infula (elfin saddle), G. caroliniana and G. gigas (snow morel). While some of these species contain little or no gyromitrin, many sources recommend treating them all as poisonous, since their similar appearance and significant intraspecific variation can make reliable identification difficult. The name is also sometimes used for mushrooms of the genus Verpa, such as V. bohemica and V. conica, also known as early morels or thimble morels.

[edit]

External links

de:Frühjahrslorchel es:Gyromitra esculenta fr:Gyromitre lt:Bobausis ja:シャグマアミガサタケ pl:Piestrzenica kasztanowata fi:Korvasieni uk:Строчок звичайний

Retrieved from "http://www.netipedia.com/index.php/False_morel"