SOME POISONOUS FUNGI

Fungi commonly produce a wide range of complex chemicals, some of which are poisonous to animals, including humans. Such poisons can be divided into two categories. One is produced by moulds that contaminate food, referred to as mycotoxins, and may cause illness or death in extreme cases. The other range of toxins is found in the fruit bodies of certain mushrooms and toadstools.

There are few species which cause fatal poisoning, but some give rise to unpleasant symptoms. For advice on what to do if you suspect someone has eaten a poisonous fungus, CLICK HERE. Please also be aware that, as with many foods, it is possible for people to have allergic reactions, so a fungus may make one person ill where another person might not react. 

The genus Amanita contains some of the few truly deadly species, including the deliciously named 'destroying angel' (Amanita virosa), a pristine white toadstool which is particularly prevalent in Scotland. Some of the poisonous species contain psychoactive compounds (often tryptamine derivatives), used in other areas of the world in religious rites. The extent to which such fungi were used in Scotland's early history is hard to determine.  However, a number of species are certainly illegally used today for recreational purposes.
 

• Cytolitic toxins - (eg: Cyclopeptides, Orellanin, Gyromytrin) are very dangerous and, as the name suggests, attack the cells of organs in which they are present, destroying the kidneys and the liver.
• Haemolytic toxins - attack red blood cells.
• Coprine poisons - inhibit acetaldehyde metabolism, causing buildup after consumption of alcohol.
• Psychotropic compounds - found in hallucinogenic mushrooms.
• Muscarine - found in several spp., most famously A. muscaria.
• Cumulative gastro-enteric poisons - come in many different types.

Amanita muscaria (Fly agaric)	Russula emetica (The sickener)	Psilocybe semilanceata (Liberty cap)
Amanita phalloides (Death Cap)	Coprinus acuminatus (Inky Cap)	Gyromitra esculenta  (Lorchel, Lorel or False Morel)

Amanita muscaria - Fly Agaric

Muscarine type
Contains the isoxasole derivatives muscimol and ibotenic acid, which produce hallucination and possibly coma.

Muscarine-type poisoning may induce sweating, running eyes, sickness and diarrhoea. Muscarine is an alkaloid and was the first fungal toxin to be characterized. Symptoms usually develop after about 15 minutes and include stimulation of the secretory glands causing profuse sweating, salivation and weeping.
This dangerous hallucinogenic fungus has traditionally been used by cultures throughout its range in ritual divination.

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Russula emetica -  The Sickener
 

Sickness and diarrhoea results if this species is eaten raw or fried. The toxic chemicals are heat sensitive, and the Sickeners are consumed in N. Europe after parboiling and careful preparation.  However, they cannot be recommended.

This is one of the species which contains gastro-enteric toxins. The specific name 'emetica' gives an indication of its effects.

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Psilocybe semilanceata- Liberty Cap or Magic Mushroom
 

 Hallucinogenic type (psychotropic poisoning):

Contains
Psilocybin and psilocin (indole derivatives).

Onset time
From immediate to after several hours, or even days later.

Symptoms
Bizarre and accentuated vision (including spectral fracturing) and hearing, vasodilation, stomach ache. Psychological impact of the alien perceptions can lead to considerable distress (a 'bad trip'), or uncontrollable hilarity.

For more information on Psilocybe semilanceata: CLICK HERE

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Amanita phalloides - Death Cap

Cytolitic type
Contains phallotoxins and amatoxins (the latter destroyed neither by cooking nor drying) which produce no symptoms until at least five hours and up to 24 hours after ingestion.

Initial symptoms include severe stomach pain, sweating, sickness and diarrhoea together with intense thirst. By this time stomach pumping or administering absorptive charcoal has limited value. Initial symptoms die down after a while, during which the toxins break down cell membranes and are not excreted.  In fact they cause kidney and liver failure, with death occurring about a week after ingestion.

Modern treatment (including large doses of  penicillin) has reduced the mortality rates to 20%.

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Coprinus acuminatus - Ink Cap

 Coprine-type :

Symptoms

No ill-effects

or

Hot flushes, palpitations, nausea, immediately on taking alcohol, as acetaldehyde builds up (the toxin, aminocyclopropanol inhibits the enzyme responsible for breaking down acetaldehyde).

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Gyromitra esculenta - Lorchel, Lorel or False Morel

Hydrazine-type

Symptoms

Extreme symptoms of vomiting, nausea, diarrhoea
Dizziness, loss of co-ordination, convulsions..., a feeling of being bloated

Onset time
7 - 10 hours after digestion

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