Amanita verna
Encyclopedia
Amanita verna, commonly known as the fool's mushroom, Destroying angel
Destroying angel
The name destroying angel applies to several similar, closely related species of deadly all-white mushrooms in the genus Amanita. They are Amanita bisporigera and A. ocreata in eastern and western North America, and A. virosa in Europe. Another very similar species, A. verna or fool's mushroom was...

or the mushroom fool, is a deadly poisonous basidiomycete fungus
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...

, one of many in the genus Amanita
Amanita
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...

. Occurring in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 in spring, A. verna associates
Mycorrhiza
A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant....

 with various deciduous and coniferous trees. The large fruiting bodies (i.e., the mushrooms) appear in summer and autumn; the caps
Pileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...

, stipe
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...

s and gills are all white in colour.

Initially described by the French botanist Jean Baptiste François Pierre Bulliard
Jean Baptiste François Pierre Bulliard
Jean Baptiste François Pierre Bulliard was a French physician and botanist....

, the fool's mushroom's specific epithet verna is derived from its springtime fruiting habit.

Description

The fool's mushroom (Amanita verna) also known as the spring destroying angel or death angel, is a close relative of Amanita phalloides, the death cap and a member of the mushroom genus Amanita
Amanita
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...

. Amanita verna, like its close relative, belongs to the subfamily Phalloideae.

The fool's mushroom is pure white, all the way to the gills and the stem. This fungus, like all amanitas, has a volva
Volva (mycology)
The volva is a mycological term to describe a cup-like structure at the base of a mushroom that is a remnant of the universal veil. This macrofeature is important in wild mushroom identification due to it being an easily observed, taxonomically significant feature which frequently signifies a...

. The fool's mushroom's cap is 5–10 cm (2–3.9 ) wide, and is about the same height.

This mushroom's lamellae is free and white, and the volva is bag-like and large. Its annulus
Annulus (mycology)
An annulus is the ring like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like...

 is white and membranous, and A. verna also does not react with potassium hydroxide
Potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...

 solution, unlike its relative
Amanita virosa
Amanita virosa
Amanita virosa, commonly known as the European destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Occurring in Europe, A. virosa associates with various deciduous and coniferous trees...

. The mushroom's spores are smooth and elliptical.

Habitat and season

The mushroom lives in Europe. The fool's mushroom is known to grow in woodlands and hardwood forests.

As the fool's mushroom other name (spring destroying angel) suggests, this toxic amanita grows in spring.

Unlike various closely related poisonous amanitas, this mushroom is not known to occur in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

.

Toxicity

Closely related to other deadly pure white amanitas, the fool's mushroom is one of the most poisonous mushrooms in the world. Just like the death cap, it contains amatoxins, primarily alpha-amanitin
Alpha-amanitin
alpha-Amanitin or α-amanitin is a cyclic peptide of eight amino acids. It is possibly the most deadly of all the amatoxins, toxins found in several species of the Amanita genus of mushrooms, one being the Death cap as well as the Destroying angel, a complex of similar species, principally A....

, which can cause liver failure. While this mushroom also contains other poisons like phallotoxins, these toxins are not behind the fatal poisoning that this mushroom, as well as all members of the subfamily Phalloideae, causes.

This mushroom's toxicity and symptoms are similar, if not identical to that of the death cap. Like other members of the subfamily Phalloideae, the fool's mushroom has been implicated in a number of serious or fatal poisonings.

There are no negative symptoms from eating this fungus until 6–24 hours after ingestion. The first symptom is simply unease. Violent cramps and diarrhoea follow. On the third day, the same symptoms repeat themselves, but while to many this may seem like a sign of recovery, most of the time it is simply a herald of the final onset of symptoms, which include kidney and liver failure due to amatoxins. At this point, drastic measures like liver transplants need to be taken, or the victim would most likely die.

The fatal dosage of this mushroom is around 30g (1 oz), though it is not recommended taking even the smallest amount of any deadly amanita, as the fatal dosage varies with the size of the person who consumes the mushroom.

Similar species

Edible species

Many edible species resembles this mushroom and other amanitas, which is why the consumption of amanitas accounts for 95% of all mushroom fatalities.

The edible mushroom Leucoagaricus leucothites very closely resembles the fool's mushroom. However, Leucoagaricus leucothites lacks a volva, unlike A. verna. Sometimes, the volva of A. verna is hidden under leaf litter or soil, raising the need to dig out rather than cut L.naucina from the ground, so as to prevent misidentification.

Various young edible Agaricus spp. closely resemble A. verna, such as the tasty field mushroom Agaricus campestris
Agaricus campestris
Agaricus campestris is commonly known as the field mushroom or, in North America, meadow mushroom. It is a widely eaten gilled mushroom closely related to the cultivated button mushroom Agaricus bisporus.-Taxonomy:...

, Agaricus silvicola
Agaricus silvicola
Agaricus silvicola, also known as the Wood Mushroom is a species of Agaricus mushroom related to the button mushroom.- Description :...

and Agaricus arvensis
Agaricus arvensis
Agaricus arvensis, commonly known as the Horse Mushroom, is a mushroom of the genus Agaricus.-Taxonomy:Described as Agaricus arvensis by Jacob Christian Schaeffer in 1762, and given numerous binomial descriptions since. Its present name arvensis means 'of the field'.-Description:The cap is similar...

. While older specimens of these do not resemble A. verna, when these fungus are young, they do resemble A. verna. All of these mushrooms lack volvas, unlike their deadly lookalike.

Amanita caesarea
Amanita caesarea
Amanita caesarea, commonly known in English as Caesar's Mushroom, is a highly regarded edible mushroom in the genus Amanita, native to southern Europe and North Africa. It has a distinctive orange cap, yellow gills and stem. Similar orange-capped species occur in North America and India...

, with its bright orange shade, does not resemble A. verna, while this fungus is in bulb stage, it is also pure white. Amanitas closely resemble each other in bulb stage.

Another group of mushrooms in the Volvariella
Volvariella
Volvariella is a genus of mushrooms with deep salmon pink gills and spore prints. They lack a ring, and have an Amanita-like volva at the stem base. Some species of Amanita look similar, but Amanita has white spores and often have a ring. Since the gills of young Volvariella are white at first,...

genus are frequently mistaken for the deadly amanitas. Volvariella volvacea
Volvariella volvacea
Volvariella volvacea is a species of edible mushroom cultivated throughout East and Southeast Asia and used extensively in Asian cuisines. In Chinese, they are called cǎogū Volvariella volvacea (also known as straw mushroom or paddy straw mushroom; syn. Volvaria volvacea, Agaricus volvaceus,...

has often been mistaken for deadly amanitas, and most of the time, they are mistaken for a relative of the fool's mushroom, the death cap (Amanita phalloides). Volvariella speciosa looks very similar to the fool's mushroom, but with close examination, one would realise that V.speciosa has salmon gills, while the fool's mushroom has white gills. Like Amanita, Volvariella species have volvas, hence their name.

Amanitopsis vaginata, formerly Amanita vaginata, can be pure white, and thus sometimes looks nearly identical to the fool's mushroom. However, unlike all Amanita species, Amanitopsis species lack rings. However, the ring of A. verna may sometimes be eaten by worms, and thus may be missing.

While in bulb stage, A. verna, as well as its relatives, are commonly mistaken for the edible puffballs, like those form the Lycoperdon
Lycoperdon
Lycoperdon is a genus of puffball mushrooms. The genus has a widespread distribution and contains about 50 species. In general, it contains the smaller species such as the pear shaped puffball and the gem studded puffball. Most of the time they grow from dead wood and if they grow through the...

or Calvatia
Calvatia
Calvatia is a genus of puffball mushrooms which includes the spectacular giant puffball C. gigantea. It was formerly classified within the now-obsolete order Lycoperdales, which, following a restructuring of fungal taxonomy brought about by molecular phylogeny, has been split; the puffballs,...

species. To prevent confusion, it is important to cut puffballs into half. If there is the outline of Amanitas cap and stem in the 'puffball', the mushroom is an amanita.

The fatal poisoning caused by the fool's mushroom and closely related species makes amateur mushroom hunters avoid any species similar to them, and buy them form a grocer instead. Unless one can truly be sure if the species he or she is digging is edible, one should never pick a similar mushroom.

Poisonous species

Of course, the other pure white amanitas, like the destroying angels (Amanita virosa
Amanita virosa
Amanita virosa, commonly known as the European destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Occurring in Europe, A. virosa associates with various deciduous and coniferous trees...

, Amanita bisporigera
Amanita bisporigera
Amanita bisporigera is a deadly poisonous species of fungus in the Amanitaceae family. It is commonly known as the eastern North American destroying angel or the destroying angel, although it shares this latter name with three other lethal white Amanita species, A. ocreata, A. verna and...

, Amanita ocreata
Amanita ocreata
Amanita ocreata, commonly known as the death angel, destroying angel, angel of death or more precisely Western North American destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Occurring in the Pacific Northwest and California floristic provinces of...

) closely resemble Amanita verna. However, unlike Amanita verna, Amanita virosa stains yellow in KOH. Pure white specimens of the death cap also look like the fool's mushroom, and sometimes, Amanita verna is considered a subspecies of Amanita phalloides.

Other toxic species of
Agaricus, such as Agaricus xanthodermus
Agaricus xanthodermus
Agaricus xanthodermus, commonly known as the yellow-staining mushroom, is a mushroom of thegenus Agaricus, which displays a strong yellow colouration at the base of the stem when cut...

, also resemble A. verna. However, Agaricus xanthodermus stains yellow if bruised, gives off a repulsive smell when cooked, and most importantly, lacks a volva.

List of similar species

Agaricus arvensis
Agaricus arvensis
Agaricus arvensis, commonly known as the Horse Mushroom, is a mushroom of the genus Agaricus.-Taxonomy:Described as Agaricus arvensis by Jacob Christian Schaeffer in 1762, and given numerous binomial descriptions since. Its present name arvensis means 'of the field'.-Description:The cap is similar...

(Horse Mushroom) : excellent edible

Agaricus campestris
Agaricus campestris
Agaricus campestris is commonly known as the field mushroom or, in North America, meadow mushroom. It is a widely eaten gilled mushroom closely related to the cultivated button mushroom Agaricus bisporus.-Taxonomy:...

(Field mushroom) : excellent edible

Agaricus silvicola
Agaricus silvicola
Agaricus silvicola, also known as the Wood Mushroom is a species of Agaricus mushroom related to the button mushroom.- Description :...

(Wood mushroom) : excellent edible

Agaricus xanthodermus
Agaricus xanthodermus
Agaricus xanthodermus, commonly known as the yellow-staining mushroom, is a mushroom of thegenus Agaricus, which displays a strong yellow colouration at the base of the stem when cut...

(Yellow-staining mushroom) : toxic or at least unpleasant-tasting (varies with consumer)

Amanita bisporigera
Amanita bisporigera
Amanita bisporigera is a deadly poisonous species of fungus in the Amanitaceae family. It is commonly known as the eastern North American destroying angel or the destroying angel, although it shares this latter name with three other lethal white Amanita species, A. ocreata, A. verna and...

(Destroying angel) : deadly poisonous

Amanita caesarea
Amanita caesarea
Amanita caesarea, commonly known in English as Caesar's Mushroom, is a highly regarded edible mushroom in the genus Amanita, native to southern Europe and North Africa. It has a distinctive orange cap, yellow gills and stem. Similar orange-capped species occur in North America and India...

(Caesar's Amanita) (bulb stage only) : excellent edible

Amanita ocreata
Amanita ocreata
Amanita ocreata, commonly known as the death angel, destroying angel, angel of death or more precisely Western North American destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Occurring in the Pacific Northwest and California floristic provinces of...

(American destroying angel) : deadly poisonous

Amanita phalloides (death cap) : deadly poisonous

Amanita virosa
Amanita virosa
Amanita virosa, commonly known as the European destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Occurring in Europe, A. virosa associates with various deciduous and coniferous trees...

(European destroying angel) : deadly poisonous

Amanitopsis vaginata (Grisette) : Edible

Calvatia
Calvatia
Calvatia is a genus of puffball mushrooms which includes the spectacular giant puffball C. gigantea. It was formerly classified within the now-obsolete order Lycoperdales, which, following a restructuring of fungal taxonomy brought about by molecular phylogeny, has been split; the puffballs,...

spp. (Giant puffballs) : (bulb stage only) : Mostly edible when young

Leucoagaricus leucothites : Edible and good, but can cause mild poisonings in some individuals

Lycoperdon
Lycoperdon
Lycoperdon is a genus of puffball mushrooms. The genus has a widespread distribution and contains about 50 species. In general, it contains the smaller species such as the pear shaped puffball and the gem studded puffball. Most of the time they grow from dead wood and if they grow through the...

spp. (Puffballs) : Mostly edible when young

Volvariella speciosa : Edible but not tasty

Volvariella volvacea
Volvariella volvacea
Volvariella volvacea is a species of edible mushroom cultivated throughout East and Southeast Asia and used extensively in Asian cuisines. In Chinese, they are called cǎogū Volvariella volvacea (also known as straw mushroom or paddy straw mushroom; syn. Volvaria volvacea, Agaricus volvaceus,...

(Paddy straw mushroom) : Edible and good

See also

  • List of Amanita species
  • List of deadly fungi
  • Mushroom poisoning
    Mushroom poisoning
    Mushroom poisoning refers to harmful effects from ingestion of toxic substances present in a mushroom. These symptoms can vary from slight gastrointestinal discomfort to death. The toxins present are secondary metabolites produced in specific biochemical pathways in the fungal cells...

  • Amanitin
    Amanitin
    Amanitin may refer to several related amatoxins:* α-Amanitin* β-Amanitin* γ-Amanitin* ε-Amanitin...

  • Alpha-amanitin
    Alpha-amanitin
    alpha-Amanitin or α-amanitin is a cyclic peptide of eight amino acids. It is possibly the most deadly of all the amatoxins, toxins found in several species of the Amanita genus of mushrooms, one being the Death cap as well as the Destroying angel, a complex of similar species, principally A....

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