Clitocybe rivulosa
Encyclopedia
Clitocybe rivulosa, commonly known as the false champignon or fool's funnel, is a 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...

 of the large genus Clitocybe
Clitocybe
Hundreds of species of mushrooms compose the fungus genus Clitocybe. They are characterized by white, off-white, buff, cream, pink, or light-yellow spores, gills running down the stem, and pale white to brown or lilac coloration. They are primarily saprotrophic, decomposing forest ground litter...

. One of several species similar in appearance, it is a small white funnel
Funnel
A funnel is a pipe with a wide, often conical mouth and a narrow stem. It is used to channel liquid or fine-grained substances into containers with a small opening. Without a funnel, spillage would occur....

-shaped toadstool widely found in lawns, meadows and other grassy areas 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...

 and 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...

. Also known as the sweating mushroom, it derives this name from the symptoms of poisoning. It contains potentially deadly levels of muscarine
Muscarine
Muscarine, L--muscarine, or muscarin is a natural product found in certain mushrooms, particularly in Inocybe and Clitocybe species, such as the deadly C. dealbata. Mushrooms in the genera Entoloma and Mycena have also been found to contain levels of muscarine which can be dangerous if ingested...

.

Description

A small white or white dusted with buff
Buff (colour)
Buff is a pale yellow-brown colour that got its name from the colour of buff leather.Displayed on the right is the colour buff.EtymologyAccording to the Oxford English Dictionary, buff as a descriptor of a colour was first used in the London Gazette of 1686, describing a uniform to be "A Red Coat...

-coloured mushroom, the 3–4 cm diameter cap
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...

 is funnel-shaped with decurrent crowded white gills, with specks of pink. The fibrous 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...

 is up to 4 cm tall and bears no ring. The spore print
Spore print
thumb|300px|right|Making a spore print of the mushroom Volvariella volvacea shown in composite: mushroom cap laid on white and dark paper; cap removed after 24 hours showing pinkish-tan spore print...

 is white. There is no distinctive taste or smell. It is one of a number of similar poisonous species such as the ivory funnel (Clitocybe dealbata
Clitocybe dealbata
Clitocybe dealbata, also known as the ivory funnel, is a small white funnel-shaped toadstool widely found in lawns, meadows and other grassy areas in Europe and North America. Also known as the sweating mushroom, it derives this name from the symptoms of poisoning...

) which can be confused with the edible fairy ring champignon (Marasmius oreades
Marasmius oreades
Marasmius oreades is also known as the scotch bonnet or fairy ring mushroom. The latter name tends to cause some confusion, as many other mushrooms grown in fairy rings .-Distribution and habitat:Marasmius oreades grows extensively throughout North America...

), or miller (Clitopilus prunulus
Clitopilus prunulus
Clitopilus prunulus, commonly known as the miller or the sweetbread mushroom, is an edible pink-spored basidiomycete mushroom found in grasslands in Europe. It has a grey to white cap and decurrent gills.-Description:...

).

Taxonomy and naming

It was initially described as Agaricus rivulosus by Christian Hendrik Persoon
Christian Hendrik Persoon
Christiaan Hendrik Persoon was a mycologist who made additions to Linnaeus' mushroom taxonomy.-Early life:...

 in 1801, before German naturalist Paul Kummer
Paul Kummer
Paul Kummer was a priest, teacher, and scientist in Zerbst, Germany, known chiefly for his contribution to mycological nomenclature. Earlier classification of agarics by pioneering fungal taxonomist Elias Magnus Fries designated only a very small number of genera, with most species falling into...

 gave it its current name in 1871.

The surface of the cap can develop concentric rings of cracks with age, and the species epithet rivulosa refers to this fissuring.

The very similar Clitocybe dealbata
Clitocybe dealbata
Clitocybe dealbata, also known as the ivory funnel, is a small white funnel-shaped toadstool widely found in lawns, meadows and other grassy areas in Europe and North America. Also known as the sweating mushroom, it derives this name from the symptoms of poisoning...

is sometimes regarded as part of the same species complex as C. rivulosa.

Distribution and habitat

The false champignon is found in grassy habitats in summer and autumn in Europe and North America, where it can often form fairy ring
Fairy ring
A fairy ring, also known as fairy circle, elf circle, elf ring or pixie ring, is a naturally occurring ring or arc of mushrooms. The rings may grow to over in diameter, and they become stable over time as the fungus grows and seeks food underground. They are found mainly in forested areas, but...

s; individual mushrooms nestled in the grass which often grows richer and greener where they occur. Unfortunately, they often occur in grassy areas where they may be encountered by children or toddlers. This may increase risk of accidental consumption.

Toxicity

The main toxic component of Clitocybe rivulosa is muscarine
Muscarine
Muscarine, L--muscarine, or muscarin is a natural product found in certain mushrooms, particularly in Inocybe and Clitocybe species, such as the deadly C. dealbata. Mushrooms in the genera Entoloma and Mycena have also been found to contain levels of muscarine which can be dangerous if ingested...

, and thus the symptoms are those of muscarine poisoning, namely, greatly increased saliva
Saliva
Saliva , referred to in various contexts as spit, spittle, drivel, drool, or slobber, is the watery substance produced in the mouths of humans and most other animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands,...

tion, perspiration (sweating), and lacrimation (tear flow) within 15-30 minutes of ingestion. With large doses, these symptoms may be followed by abdominal
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

 pain, severe nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

, blurred vision, and labored breathing. Intoxication generally subsides within two hours. Death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

 is rare, but may result from cardiac or respiratory failure
Respiratory failure
The term respiratory failure, in medicine, is used to describe inadequate gas exchange by the respiratory system, with the result that arterial oxygen and/or carbon dioxide levels cannot be maintained within their normal ranges. A drop in blood oxygenation is known as hypoxemia; a rise in arterial...

 in severe cases. The specific antidote
Antidote
An antidote is a substance which can counteract a form of poisoning. The term ultimately derives from the Greek αντιδιδοναι antididonai, "given against"....

 is atropine
Atropine
Atropine is a naturally occurring tropane alkaloid extracted from deadly nightshade , Jimson weed , mandrake and other plants of the family Solanaceae. It is a secondary metabolite of these plants and serves as a drug with a wide variety of effects...

.
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