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

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Ba ...

fungus A fungus ( : fungi or funguses) is any member of the 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, separately from t ...

of the large genus ''

Clitocybe ''Clitocybe'' is a genus of mushrooms 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 grou ...

''. One of several species similar in appearance, it is a small white

funnel A funnel is a tube or pipe that is wide at the top and narrow at the bottom, used for guiding liquid or powder into a small opening. Funnels are usually made of stainless steel, aluminium, glass, or plastic. The material used in its construct ...

-shaped

toadstool A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is th ...

widely found in lawns, meadows and other grassy areas in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

and North America. Also known as the sweating mushroom, it derives this name from the symptoms of poisoning (

SLUDGE syndrome A cholinergic crisis is an over-stimulation at a neuromuscular junction due to an excess of acetylcholine (ACh), as a result of the inactivity of the AChE enzyme, which normally breaks down acetylcholine. Symptoms and diagnosis As a result of c ...

). It contains potentially deadly levels of

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 ...

Description

A small whitish mushroom, the 3–4 cm diameter

cap A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

is funnel-shaped with decurrent crowded white gills, with specks of pink. The fibrous stipe is up to 4 cm tall and bears no ring. The

spore print 300px, Making a spore print of the mushroom ''Volvariella volvacea'' shown in composite: (photo lower half) mushroom cap laid on white and dark paper; (photo upper half) cap removed after 24 hours showing pinkish-tan spore print. A 3.5-centimeter ...

is white. There is no distinctive taste or smell. It is one of a number of similar poisonous species, which can be confused with the edible fairy ring champignon ('' Marasmius oreades'') or miller (''

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 and North America. Growing solitary to gregarious in open areas of conifer/hardwood f ...

''), such as the ivory funnel (''

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 th ...

'') . When young and imbued with moisture, as with a small group of related ''Clitocybes ''such as ''C. phyllophila, ''the cap has a distinctive brownish translucent aspect with a "frosting" of white (which however is not superficial, but part of the flesh). When it dries out it becomes uniform pure white, and it is more difficult to identify. Thus it is

hygrophanous The adjective hygrophanous refers to the color change of mushroom tissue (especially the pileus surface) as it loses or absorbs water, which causes the pileipellis to become more transparent when wet and opaque when dry. When identifying hygroph ...

in a way, but not to be confused with the smaller thin-fleshed ''Clitocybe'' species which are commonly characterized as hygrophanous. As in other keys which could be used as references, the frosted appearance of the cap described in the article is used to distinguish this group of ''Clitocybes''.

Taxonomy and naming

It was initially described as ''Agaricus rivulosus'' by

Christian Hendrik Persoon Christiaan Hendrik Persoon (1 February 1761 – 16 November 1836) was a German mycologist who made additions to Linnaeus' mushroom taxonomy. Early life Persoon was born in South Africa at the Cape of Good Hope, the third child of an i ...

in 1801, before German naturalist

Paul Kummer Paul Kummer (22 August 1834 – 6 December 1912) was a minister, teacher, and scientist in Zerbst, Germany, known chiefly for his contribution to mycological nomenclature. Earlier classification of agarics by pioneering fungal taxonomist Elias Ma ...

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 ''

'' is sometimes regarded as part of the same species as ''C. rivulosa, ''and in that case the name ''rivulosa ''takes precedence and should be used for all these fungi. If distinguished, it is on the basis that build is more robust, the gills are less decurrent and the margin has a tendency to crack up.

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 A fairy ring, also known as fairy circle, elf circle, elf ring or pixie ring, is a naturally occurring ring or arc of mushrooms. They are found mainly in forested areas, but also appear in grasslands or rangelands. Fairy rings are detectable by ...

s; individual mushrooms nestled in the grass which often grows richer and greener where they occur. 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 toxin in ''Clitocybe rivulosa'' is

, and thus the symptoms are somewhat like that of nerve agent exposure, namely, greatly increased salivation,

perspiration Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distr ...

(sweating), and

lacrimation Tears are a clear liquid secreted by the lacrimal glands (tear gland) found in the eyes of all land mammals. Tears are made up of water, electrolytes, proteins, lipids, and mucins that form layers on the surface of eyes. The different types of ...

(tear production) within 15–30 minutes of ingestion. With large doses, these symptoms may be followed by

abdominal The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso ...

pain, severe

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...

, blurred vision, and labored breathing. Intoxication generally subsides within two hours.

Death Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...

is rare, but may result from

respiratory failure Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise ...

in severe cases. The specific

antidote An antidote is a substance that can counteract a form of poisoning. The term ultimately derives from the Greek term φάρμακον ἀντίδοτον ''(pharmakon) antidoton'', "(medicine) given as a remedy". Antidotes for anticoagulants are s ...

is atropine.

References

External links