Every year, thousands of people around the world become ill or die after ingesting toxic mushrooms.
Whether you are an avid forager or simply curious to know 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, along with their health effects, how to identify them, and fascinating facts about how dangerous they are.
1. Amanita phalloides (Amanita phalloides)
Known as the "Death Hat", the Amanita phalloides is responsible for the majority of fatal mushroom poisonings worldwide. It has an olive green cap, white blades and a white volva.
This amanita is probably also involved in the deaths of certain famous historical figures such as the Roman Emperor Claudius 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 such as meadow rose or coumelles, which represents a great danger for 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 honey mushrooms. However, it is extremely toxic and contains deadly toxins similar to those of the amanita phalloides.
For example, in 2008, a group of hikers in Oregon ate Galerina marginata thinking they were honey mushrooms. One of them died while the others suffered serious kidney failure.
- Toxins: Amanitin, identical to that present in the amanita phalloides.
- Identification risks: Frequent confusion with edible species such as the honey mushroom (Armillaria mellea), which increases 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. Annatto-colored cortinaria (Cortinarius rubellus)
Annatto-colored mushroom is an orange-brown mushroom, often found in forests. It contains a toxin called orellanin which causes serious 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 serious kidney symptoms such as reduced urine production and back pain.
- Onset Time: Symptoms may 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 pickers who mistook it for a medicinal mushroom.
- Effects of poisoning: Vomiting, diarrhea, fever, hair loss, multiorgan failure.
- Anecdote: The number of deaths attributed to this fungus 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. Gyromitre (Gyromitra esculenta)
Nicknamed the “brain mushroom” due to its wrinkled appearance, Gyromitre is extremely toxic. It contains gyromitrin, which turns into a powerful toxin when ingested. In Finland, despite its toxicity, it is sometimes consumed after having been carefully prepared, but cases of poisoning persist every year.
- Symptoms: Nausea, vomiting, seizures, abdominal pain, and possible liver and central nervous system damage.
- Advice: Never consume this mushroom without appropriate preparation (repeated boiling and drying).
Source : Michelot, D., & Toth, B. (1991). "Poisoning by Gyromitra esculenta—A Review". Journal of Applied Toxicology.
6. Clitocybe blanc (Clitocybe dealbata)
White Clitocybe is a small mushroom that often grows in lawns and meadows. It contains muscarine, a toxin dangerous to humans. In 2014, in the south of France, a 3-year-old child was hospitalized after ingesting this mushroom in his garden. Fortunately, thanks to rapid medical intervention, he survived.
- Symptoms: Hyper-salivation, excessive sweating, vomiting, diarrhea, vision problems.
- Risks: Given its small size, it is easy to miss when picking, increasing the risk of accidental ingestion.
Source : Noordeloos, M. E. (2012). Fungi of Temperate Europe. Princeton University Press.
7. Lepiota brunneoincarnata (Lepiota brunneoincarnata)
The Crimson-brown Lepiote is a small mushroom often mistaken for edible species, but it is highly toxic and contains amanitin. In Spain, several fatal poisonings were reported in the early 2000s when people mistook these mushrooms for 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 serious liver damage.
Source: Assailly, C., et al. (2003). Mushrooms: Recognize them, pick them, cook them. Paris: Delachaux and Niestlé.
8. Inocybe de Patouillard (Inocybe erubescens)
Patouillard's Inocybe is a toxic mushroom with white lamellae that turn reddish. It contains muscarine, a neurotoxic toxin. In Germany in 2012, a family mistook this mushroom for an edible species, leading to emergency hospitalization after severe gastrointestinal upset and respiratory distress.
- Effects: Hyper-salivation, sweating, vomiting, abdominal pain, hypotension 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 serious gastrointestinal poisoning. In Australia, a family of five was hospitalized after eating this mushroom, believing it to be a parasol mushroom (Macrolepiota procera).
- Symptoms: Nausea, vomiting, severe diarrhea which 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. Jack O'Lantern (Jack O'Lantern)
The Omphalotus illudens, or "Jack O'Lantern" mushroom, is often confused with edible chanterelles. This bioluminescent mushroom, glowing in the dark, contains toxins that cause serious gastrointestinal upset. In the United States, many cases of poisoning occur each year due to this confusion.
- Symptoms: Vomiting, severe diarrhea, abdominal pain lasting 12 to 48 hours.
- Fun Fact: Its bioluminescence has inspired tales of witchcraft 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
Rely on mobile mushroom recognition applications?
Mobile mushroom recognition apps can be valuable allies for nature lovers and mushroom enthusiasts, providing unprecedented convenience and accessibility. In an instant, they make it possible to identify species, discover information on their toxicity or edibility, and access extensive databases.
However, these apps are not foolproof and should be used with discretion. Identification accuracy 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, proven resources, such as specialized mycological guides or advice from experienced mycologists. Mycology is a complex science where many species resemble each other, and misidentification can have serious or even fatal consequences.
Hands-on learning, field experience, and expert consultation remain essential for anyone wishing to safely explore the world of mushrooms.
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 confusing 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 what to do and tips to avoid these situations.
What to do if you think you have eaten poisonous mushrooms?
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Don't wait for symptoms: Symptoms of mushroom poisoning can vary depending on the toxin and the species consumed. They can appear quickly (within 30 minutes) or after several hours or even days. If you think you have eaten a poisonous mushroom, it is important to act immediately, even if there are no symptoms.
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Call medical emergencies (Samu or poison control center): If you experience symptoms or suspect that you have consumed a dangerous mushroom, immediately call the emergency services (Samu - 15 in France) or a center anti-poison. Try to provide specific information about the mushrooms eaten: where they were found, what they looked like, and how they were cooked.
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Save leftover mushrooms: If possible, save leftovers, uncooked mushrooms or cleaning waste. These elements can help doctors and mycologists to identify the species(s) responsible for the poisoning and thus adapt the treatment.
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Do not induce vomiting: Unless specifically recommended by a healthcare professional, do not induce vomiting. This practice can make the situation worse 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, seizures, or other neurological disorders
- Kidney or liver failure (in severe cases)
In the most severe cases, the ingestion of toxic mushrooms such as amanita phalloides can lead to irreversible damage to the liver and kidneys.
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Hospitalization and treatment: Rapid hospitalization is often necessary in cases of serious poisoning. Doctors can administer specific treatments, such as antidotes (when available), activated charcoal to limit the absorption of toxins, 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 the identification of mushrooms before eating them. Learning is best done by following 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’s better to be careful than 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 applications, but they do not replace human expertise.
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Only pick mushrooms that you know well: Limit your picking to mushrooms that you have learned to identify with certainty and that you have already eaten without problem. Pay particular attention to mushrooms that resemble toxic species, such as amanitas, often confused with edible species.
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Avoid unsafe picking locations: Mushrooms can absorb environmental pollutants, so avoid picking near roads, industrial sites, or in areas likely to be contaminated.
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Consult a pharmacist or mycologist: In France, many pharmacists are trained to identify mushrooms. You can also consult a mycologist or mycology company to identify your pickings before consuming them.
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Do not trust 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 whether they are cooked in vinegar are not reliable indicators of their safety.
Conclusion
Knowing about poisonous mushrooms is essential to avoid potentially fatal mistakes. When picking, it is essential to correctly identify mushrooms and always consult an expert if in doubt.
Use trusted resources, like mycology books or mobile apps, to help you identify mushrooms and stay safe.
