Toxic fungi

This web page is not intended to give comprehensive information about the identification of poisonous fungi and you should always consult a guide book or an expert before eating any wild fungi.

Please be aware that there are no general rules that can reliably tell you whether or not a fungus is edible. Some people can be allergic even to shop mushrooms, so when trying a species for the first time, just eat a small amount and see how you get on with it.

Below are some of the species involved, arranged in alphabetical order. Some of these species are more poisonous than others and this list is by no means comprehensive. The advice given on the main page about identifying and eating wild fungi should always be followed.

If you suspect that you, or someone in your care, has been poisoned by mushrooms, you should go directly to your nearest Accident and Emergency Department. There the staff will contact The National Poisons Information Service (NPIS) and, with their help, will determine which poisoning syndrome* is indicative of the symptoms presented. The most important information you can give the staff is the length time elapsed since the mushroom was consumed. If possible you should try to collect a specimen to take with you or at least describe the mushroom and the habitat from which it was found. However, it is often the case that it will not be possible to identify the mushroom. The time taken for the onset of the first symptoms will indicate the toxins involved as shown in the attached diagnostic flow chart* at the bottom of this page.

*information provided here for guidance only - Not offical NPIS documents.

Amanita virosa Destroying Angel. Another of the deadly Amanita genus with very similar toxins causing similar symptoms to the Death Cap Amanita phalloides.Identification: All members of this genus have a white spore print and gills that are free of the stem. This fungus is white throughout and the cap is often conical and set at a jaunty angle. There is a large white ring on the stem and a large sac like volva that the stem arises from. The smell is sweet and rather nauseous although some might find it pleasant. The smell is also sometimes described as smelling of fountain pen ink. Note how the cap changes shape as it developsLook a likes: The most dangerous confusion would be between this species and members of the field mushroom species (Agaricus), which have a dark purple brown spore print. It would also be possible to confuse it with edible members of the pink spored genus Volvariella and other members of the genus Amanita which are best avoided. When it is very small and still contained as a button within the white universal veil, it could easily be mistaken for an edible puffball. Such a mistake would be revealed by cutting through the button - the immature mushroom would be visible within the structure.

Habitat: This species is present in Scotland and can be locally abundant. It has been recorded in one of the green spaces of Edinburgh and you should not be complacent when many books describe it as rare or occasional. It is a mycorrhzial species usually growing with birch on acid soils but has been recorded under other broadleaves and conifers.

Clitocybe rivulosa Fool's Funnel is another species that contains large amounts of muscarine, a substance that causes sweating and vomiting and can cause severe health problems.

Identification: Small whitish species with white spores and crowded gills that are decurrent (running down the stem). No veil remains. The smell is variously described as sweetish or mealy.

Look a likes: Most likely to be confused with Marasmius oreades (Fairy Ring Champignon)as they grow in the same grassland habitat.The latter species has a more tan coloured cap and broadly spaced, adnexed gills. Clitocybe rivulosa could also be confused with Agaricus species although these have dark purple brown spores and veil remains are usually visible. Another species that could be confused here is Clitopilus prunulus (The Miller) as it too smells mealy and has decurrent gills. The spores of this species are however pink.

Habitat: Grows amongst grass in lawns, parks, roadsides and pastures.

Coprinus atramentarius Common Inkcap. This is one of a selection of fungi that contains an amino acid called Coprine. This substance is not harmful unless you drink alcohol within 48 hours of consuming the fungus. The result is the rapid onset of unpleasant symptoms including sweating and vomiting.Identification: The pale brown, rather egg shaped caps have tiny tan coloured scales near the centre. As they age the caps autodigest into a dripping, black fluid, rarely surviving long enough to open up into the usual toadstool umbrella shape. The spores are black.Look a likes: This species is often mistaken for its close relative Coprinus comatus Shaggy Ink Cap or Lawyers Wig but this species has large, white scales on the cap as its common names suggest.

Habitat: It grows in large clustered groups around the base of living and dead trees. Sometimes they occur way from trees, most likely arising from buried dead wood and can appear wherever there is dead wood.

Cortinarius rubellus Deadly Webcap (used to be called Cortinarius speciosissimus and will appear in some field guides under that name). As the English name suggests, this is not a fungus to mistake for Cantharellus cibarius the Chanterelle, as is recorded as having happened in the past. This species has been responsible for several severe poisoning episodes in Scotland and recent cases of kidney failure. The group of compounds responsible is orellanin and these are not destroyed by cooking the fungus.

Identification: If you know what to look for, there should be no difficulty in avoiding this species. The spore print is bright rusty brown and the young fruit body has a cortina (cobwebby veil stretching from the edge of the cap to the stem) which is most easy to see in young fruit bodies. the gills are more or less adnate (extending from the gill edge across to and joining the stem for the full depth of the gill but not running down the stem). It has bright brown colours throughout and usually a cap with a conical outline (some books describe this as umbonate). The gills are distant and broad and the stem is covered with almost snakeskin like girdles of yellowish veil remains. A pleasant radishy smell can sometimes be detected.

Look a likes: There are several other Cortinarius species that fit this description - none of them should be eaten. If people can convince themselves that this species is a Chanterelle (which has egg yolk yellow colours throughout, off white spores and no veil remains of any kind), then there is almost no point in offering look a likes! Never convince yourself from a photograph or memory. Always look at the evidence in front of you and if you have any doubts then do not eat the fruit body.

Habitat: Usually found in coniferous forests of pine or spruce and forests of mixed birch and pine. The fungus is mycorrhizal with the trees and fruit bodies often occur in moss beds, including Spaghnum species.

Gyromitra esculenta False Morel. Although traditionally eaten in Finland and several other European countries, it has always been known that this fungus requires careful preparation to breakdown the toxin it contains. Even so it is not recommended that this be eaten as it also contains carcinogenic hydrazines. Interestingly, if not destroyed, the toxin (Gyromitrin) breaks down in the human stomach producing a substance very similar to certain types of rocket fuel! Definitely not one to confuse with the edible Morel!Identification: Usually growing to about the size of a fist, this species is one of the spore shooters (ascomycetes) and does not have gills, pores or tubes. The tan or red brown cap has a rather brain like appearance and is supported by a whitish stem.

Look a likes: This appears in the spring, at the same time as Morchella esculenta (Morel) and superficially they appear similar. The cap of Gyromitra esculenta is however convoluted and 'brain' like whereas Morchella esculenta has a distinctly honeycombed appearance, composed of discrete 'pits'. The stem of Gyromitra is multi chambered whereas that of Morchella is completely hollow and without subdivisions.

Habitat: This species is locally abundant in Scotland in the spring and is usually found in coniferous woodland. It is a wood rotting species and does sometimes turn up on broadleaved wood. It can also appear in wood chips in gardens.

Hygrophoropsis aurantiaca False Chanterelle This species is very common, particularly in conifer woodlands. It is often mistaken for Cantharellus cibarius as the two fungi have several characters in common, including similar colours and decurrent gills (running down the stem). A small percentage of the population report that eating it has caused sickness. The active component causing this problem has not been investigated and as the species is not particularly tasty to eat, it is recommended that you learn to distinguish it from Chanterelle and avoid eating it.

Identification: Orange colours throughout with a dry cap and gills that are decurrent. The spores are whitish in colour and there are no veil remnants.

Look a likes: Cantharellus cibarius Chanterelle (or Girolle) - this has egg yolk yellow colours (OK, thinking organic egg yolks here not supermarket pale yolks!) without the orange tones of Hygrophoropsis aurantiaca. Chanterelle sometimes smells of apricots. Technically, a Chanterelle does not have true gills but 'wrinkles'; this is not a particularly obvious feature in the field.

Habitat: Almost always a species of coniferous or mixed woodland

Here are Hygrophoropsis aurantiaca (left) and Cantharellus cibarius (right) side by side. The colour difference is subtle but distinct, particularly in the gills. Expert guidance and experience will help you gain a feel for the giz

Paxillus involutus Brown Rollrim. This is another species with a history of being eaten in parts of Europe. Some people are however, very sensitive to this species and eating it causes sickness and in some cases, liver and kidney damage. It seems that the toxins build up and have a cumulative effect causing death in some instances.

Identification: The rim of the cap tends to stay inrolled even when the cap is fully mature. The cap is a yellowy brown colour as are the gills, all areas will bruise reddish brown. The gills are decurrent (running down the stem) and can easily be removed from the cap flesh by running your thumb underneath them. The cap texture is very variable however and can be dry and velvety or smooth and slimy when wet. Spore colour is olive brown. There are several species hidden within most people's concept of this species but it is likely that they should all be avoided as wild food.

Look a likes: Unlikely to be confused with any of the well known edible species

Habitat: This species is mycorrhizal and occurs in most woodland types and also in gardens and parks near trees. It is particularly common with birch.

Paxillus involutus Brown Rollrim

Psilocybe semilanceata Liberty Cap or Magic Mushroom. When this species is eaten, psychotropic poisoning is caused by the indole compounds, psilocin and psilocybin that are present in the fruit body. It is now illegal to possess any fungus containing these substances - although the law does allow that where the fungus is just growing in a lawn or field, the owner is not considered to be in possession of a Class A drug! Further guidelines on the Drugs Act.

identification: This is a small species with the cap rarely more than 1cm across and the slender stem rarely longer than 10cm. the cap is dull brown, often sticky and rarely opens out fully. This coupled with the presence of a distinct pimple in the middle of the cap has given the common name 'Liberty Cap' an interesting second meaning- that of being the shape of the hat worn by the men in the French Revolution - talk about loosing your head....

Look a likes: most of the look a likes are other small brown jobs growing in similar habitats. None of these species are recommended eating.

Habitat: found in most grassland habitats, often those that are fairly nitrogen rich.

Further general information on edibility is available in most field guides although particularly recommended is:

'Collins How to Identify Edible Mushrooms' by Patrick Harding, Tony Lyon and Gill Tomblin. This is published by HarperCollins.

More specific information about fungal poisoning is also available:

Children and Toxic Fungi: The essential medical guide to fungal poisoning in children

by Roy Watling (1995)

ISBN 1 872291 16 3, softback, 56pp, £7.50 plus £1.00 p+p (UK)

and:

'Posionous Plants and Fungi in Britain and Ireland' a cd and booklet available from RBGK http://www.kew.org/data/poisplts.html