Every year, thousands of people worldwide become ill or lose their lives after ingesting toxic mushrooms.
Whether you are a picking enthusiast or simply curious to learn more about these sometimes deadly wonders of nature, it is essential to know the dangers posed by certain mushrooms.
In this article, we present the 10 most toxic mushrooms in the world, their health effects, how to identify them, and fascinating anecdotes about their danger.
1. Amanita phalloides (Amanita phalloides)
Known as the "Death Cap," the Amanita phalloides is responsible for the majority of fatal mushroom poisonings worldwide. It has an olive green cap, white gills, and a white volva.
This amanita is probably responsible for the death of some famous historical figures such as the Roman emperor Claude or the Holy Roman Emperor Charles VI.
- Toxins: Contains amanitin, a toxin that causes irreversible damage to the liver and kidneys.
- Effects of poisoning: Severe gastrointestinal symptoms (nausea, vomiting, diarrhea) followed by liver and kidney failure in the days that follow.
- Risks: Often confused with edible mushrooms like the meadow mushrooms or parasol mushrooms, which poses a great danger to amateur pickers.
Source: Benjamin, D. R. (1995). Mushrooms: Poisons and Panaceas. New York: WH Freeman and Company.
2. Galerina marginata
This small brown mushroom often grows on rotting wood and resembles edible mushrooms like the honey mushroom. However, it is extremely toxic and contains deadly toxins similar to those of the death cap mushroom.
For example, in 2008, a group of hikers in Oregon consumed Galerina marginata thinking they were honey mushrooms. One of them died while the others suffered severe kidney failure.
- Toxins: Amanitin, identical to that found in the death cap mushroom.
- Identification risks: Frequent confusion with edible species like the honey mushroom (Armillaria mellea), increasing the risk of poisoning.
- Symptoms: Abdominal pain, vomiting, diarrhea, which can progress to kidney and liver failure.
Source: Beug, M. W., Shaw, M., & Cochran, K. W. (2006). "Thirty-Plus Years of Mushroom Poisoning: Summary of the Approximately 2,000 Reports in the NAMA Case Registry". McIlvainea.
3. Cortinarius orellanus (Cortinarius rubellus)
The Cortinarius orellanus is an orange-brown mushroom often found in forests. It contains a toxin called orellanine that causes severe kidney damage.
Anecdote: In 1979, a Swedish scientist, after eating a mushroom soup containing this mushroom, had to be treated with dialysis for several weeks to avoid permanent kidney failure.
- Symptoms: Nausea, vomiting, abdominal pain followed by severe kidney symptoms such as reduced urine output and back pain.
- Onset time: Symptoms can appear 2 to 17 days after ingestion, making diagnosis difficult.
Source: Bresinsky, A., & Besl, H. (1990). A Colour Atlas of Poisonous Fungi. Wolfe Publishing Ltd.
https://www.mycodb.fr/fiche.php?genre=Cortinarius&espece=speciosissimus&numphoto=5&source=list&filter=&numfiche=1989
4. Podostroma cornu-damae
This red mushroom, rare and mainly found in Asia, is extremely toxic. It contains trichothecenes, mycotoxins that can cause hair loss, organ failure, and death. An outbreak of deaths in 1999 in Japan was linked to the consumption of this mushroom by foragers who confused it with a medicinal mushroom.
- Effects of poisoning: Vomiting, diarrhea, fever, hair loss, multiorgan failure.
- Anecdote: The number of deaths attributed to this mushroom led to a public information campaign in Japan.
Source: Hall, I. R., et al. (2003). Edible and Poisonous Mushrooms of the World. Timber Press.
5. Gyromitra (Gyromitra esculenta)
Nicknamed the "brain mushroom" due to its wrinkled appearance, the Gyromitra is extremely toxic. It contains gyromitrin, which transforms into a powerful toxin once ingested. In Finland, despite its toxicity, it is sometimes consumed after careful preparation, but poisoning cases still occur every year.
- Symptoms: Nausea, vomiting, convulsions, abdominal pain, and possible damage to the liver and central nervous system.
- Advice: Never consume this mushroom without proper preparation (repeated boiling and drying).
Source: Michelot, D., & Toth, B. (1991). "Poisoning by Gyromitra esculenta—A Review". Journal of Applied Toxicology.
6. White Clitocybe (Clitocybe dealbata)
The white Clitocybe is a small mushroom that often grows in lawns and meadows. It contains muscarine, a toxin dangerous to humans. In 2014, in southern France, a 3-year-old child was hospitalized after ingesting this mushroom in his garden. Fortunately, thanks to rapid medical intervention, he survived.
- Symptoms: Hypersalivation, excessive sweating, vomiting, diarrhea, vision disturbances.
- Risks: Due to its small size, it is easy to miss during picking, thus increasing the risk of accidental ingestion.
Source: Noordeloos, M. E. (2012). Fungi of Temperate Europe. Princeton University Press.
7. Brown-incarnate Lepiota (Lepiota brunneoincarnata)
The brown-incarnate Lepiota is a small mushroom often confused with edible species, but it is highly toxic and contains amanitin. In Spain, several fatal poisonings were reported in the early 2000s when people confused these mushrooms with edible parasol mushrooms.
- Risks: Frequent confusion with edible mushrooms of the same family, especially by inexperienced pickers.
- Effects: Symptoms similar to those caused by amanitin, leading to severe liver damage.
Source: Assailly, C., et al. (2003). Mushrooms: How to recognize, pick, and cook them. Paris: Delachaux et Niestlé.
8. Patouillard's Inocybe (Inocybe erubescens)
Patouillard's Inocybe is a toxic mushroom with white gills that turn reddish. It contains muscarine, a neurotoxic toxin. In Germany, in 2012, a family confused this mushroom with an edible species, resulting in an emergency hospitalization after severe gastrointestinal disorders and respiratory distress.
- Effects: Hypersalivation, sweating, vomiting, abdominal pain, low blood pressure, and severe respiratory distress.
- Treatment: Administration of atropine in case of severe poisoning.
Source: Buczacki, S., Shields, C., & Ovenden, D. (2012). Collins Fungi Guide: The Most Complete Field Guide to the Mushrooms and Toadstools of Britain & Ireland. HarperCollins Publishers.
9. Chlorophyllum brunneum
Chlorophyllum brunneum is often confused with edible mushrooms, but it causes severe gastrointestinal poisoning. In Australia, a family of five was hospitalized after eating this mushroom, believing it was a parasol mushroom (Macrolepiota procera).
- Symptoms: Nausea, vomiting, severe diarrhea that can lead to significant dehydration.
- Risks: Confusion with edible species of the same family increases the risk of accidental poisoning.
Source: Young, A. M. (2005). A Field Guide to the Fungi of Australia. UNSW Press.
https://www.mycodb.fr/fiche.php?genre=Chlorophyllum&espece=brunneum
10. Omphalotus illudens (Jack O'Lantern)
Omphalotus illudens, or the "Jack O'Lantern" mushroom, is often confused with edible chanterelles. This bioluminescent mushroom, glowing in the dark, contains toxins that cause severe gastrointestinal disorders. In the United States, many poisoning cases occur each year due to this confusion.
- Symptoms: Vomiting, severe diarrhea, abdominal pain lasting 12 to 48 hours.
- Anecdote: Its bioluminescence inspired witchcraft tales in American folklore.
Source: Lincoff, G. H. (1981). The Audubon Society Field Guide to North American Mushrooms. Knopf.
https://fr.wikipedia.org/wiki/Omphalotus_illudens
Relying on mobile mushroom recognition apps?
Mobile mushroom recognition apps can be valuable allies for nature lovers and mushroom enthusiasts, offering unprecedented convenience and accessibility. In an instant, they allow identification of species, discovery of information about their toxicity or edibility, and access to extensive databases.
However, these applications are not infallible and must be used with discernment. The accuracy of identification often depends on the quality of the photo, the algorithms used, and the variety of mushrooms in the database.
For serious mushroom pickers, these digital tools should never replace traditional and proven resources, such as specialized mycological guides or advice from experienced mycologists. Mycology is a complex science where many species look alike, and misidentification can have serious, even fatal, consequences.
Hands-on learning, field experience, and consulting experts remain essential for anyone wishing to explore the world of mushrooms safely.
What to do in case of suspected consumption of toxic mushrooms and how to avoid it?
Toxic mushrooms are a major concern for wild mushroom enthusiasts, as confusion between edible and toxic species can have serious health consequences. If you think you have consumed potentially toxic mushrooms, it is crucial to act quickly. Here is a guide to the measures to take and advice to avoid these situations.
What to do if you think you have consumed toxic mushrooms?
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Do not wait for symptoms: Mushroom poisoning symptoms can vary depending on the toxin and the species consumed. They may appear quickly (within 30 minutes) or after several hours, even days. If you think you have eaten a toxic mushroom, it is important to act immediately, even in the absence of symptoms.
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Call medical emergency services (Samu or poison control center): If you experience symptoms or suspect you have consumed a dangerous mushroom, immediately call emergency services (Samu - 15 in France) or a poison control center. Try to provide precise information about the mushrooms consumed: where they were found, their appearance, and how they were cooked.
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Keep leftover mushrooms: If possible, keep leftovers from the meal, uncooked mushrooms, or cleaning waste. These items can help doctors and mycologists identify the species responsible for the poisoning and thus adapt the treatment.
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Do not induce vomiting: Unless expressly recommended by a healthcare professional, do not induce vomiting. This practice can worsen the situation or damage the airways.
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Watch for common symptoms of poisoning: Symptoms can vary depending on the type of mushroom, but here are common signs of poisoning to watch for:
- Nausea, vomiting, and abdominal pain
- Diarrhea
- Confusion or disorientation
- Excessive sweating or salivation
- Blurred vision or dizziness
- Cramps, convulsions, or other neurological disorders
- Kidney or liver failure (in severe cases)
In the most severe cases, ingestion of toxic mushrooms like amanite phalloïde can cause irreversible damage to the liver and kidneys.
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Hospitalization and treatment: Rapid hospitalization is often necessary in cases of severe poisoning. Doctors may administer specific treatments, such as antidotes (when they exist), activated charcoal to limit toxin absorption, or even an organ transplant in case of irreversible damage.
How to avoid consuming toxic mushrooms?
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Learn to identify mushrooms: The first and most important rule is to be absolutely certain of mushroom identification before consuming them. Learning is best done by attending training with experienced mycologists, mycology clubs, or organized outings. Never rely on vague criteria (color, smell, or location) to identify an edible mushroom.
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Avoid consuming unidentified mushrooms: If you have the slightest doubt about the identification of a mushroom, do not consume it. It is better to be cautious than to risk potentially fatal poisoning.
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Rely on specialized guides: Use reliable and up-to-date mushroom guides with quality photos. There are also mushroom recognition apps, but they do not replace human expertise.
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Only pick mushrooms you know well: Limit your foraging to mushrooms you have learned to identify with certainty and have already consumed without problems. Be especially careful with mushrooms that resemble toxic species, such as amanitas, often confused with edible species.
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Avoid risky foraging locations: Mushrooms can absorb environmental pollutants, so avoid picking near roads, industrial sites, or areas likely to be contaminated.
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Consult a pharmacist or a mycologist: In France, many pharmacists are trained to identify mushrooms. You can also consult a mycologist or a mycology society to identify your foraged mushrooms before consuming them.
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Do not rely on popular beliefs: Many myths surround toxic mushrooms. For example, the belief that mushrooms eaten by animals are necessarily edible for humans is false. Likewise, the color of mushrooms, their interaction with garlic or silver coins, or the fact that they cook in vinegar are not reliable indicators of their safety.
Conclusion
Knowing toxic mushrooms is essential to avoid potentially fatal mistakes. When foraging, it is crucial to properly identify mushrooms and always consult an expert if in doubt.
Use reliable resources, such as mycology books or mobile apps, to help you identify mushrooms and stay safe.
