Clitocybe dealbata

The ivory funnel (Clitocybe dealbata) 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. It contains potentially deadly levels of muscarine, much higher than the fly agaric (Amanita muscaria) from which the toxin was initially discovered.

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Taxonomy and naming

Clitocybe dealbata was initially described by British naturalist James Sowerby in 1799 as Agaricus dealbatus, its specific epithet derived from the Latin verb dealbare 'to whitewash'.^[1] It gained its current name in 1874 when reclassified by French naturalist Claude Casimir Gillet.^[2]

Description

A small white or white dusted with buff-coloured mushroom, the 2-4 cm diameter cap is flattened to depressed with adnate to decurrent crowded white gills. The stipe is 2-3.5 cm tall and 0.5-1 cm wide. The spore print is white. There is no distinctive taste or smell.^[3]

It is one of a number of similar poisonous species such as the false champignon (C. rivulosa) which can be confused with the edible Marasmius oreades.

Distribution and habitat

The ivory funnel is found in grassy habitats in summer and autumn. Often gregarious, it can form fairy rings.^[4] Unfortunately, they often occur in grassy areas where they may be encountered by children or toddlers. This may increase risk of accidental consumption.^[5]

Toxicity

The main toxic component of Clitocybe dealbata is muscarine, and thus the symptoms are those of muscarine poisoning, namely greatly increased salivation, sweating (perspiration), and tearflow (lacrimation) within 15-30 minutes of ingestion. With large doses, these symptoms may be followed by abdominal pain, severe nausea, diarrhea, blurred vision, and labored breathing. Intoxication generally subsides within two hours. Death is rare, but may result from cardiac or respiratory failure in severe cases. The specific antidote is atropine.^[5]

References