10 of the Most Poisonous Mushrooms on Earth

Mushrooms can be a delightful culinary treat—or a deadly mistake. While thousands of mushroom species flourish in forests, fields, and gardens worldwide, a small percentage are dangerously toxic to humans. Of the estimated 70–80 poisonous mushroom species known to science, only a handful are truly lethal when ingested. However, many of these deadly fungi closely resemble edible varieties, making them especially treacherous for foragers. In this article, we explore ten of the world’s most poisonous mushrooms. Whether you’re a mushroom enthusiast, a casual hiker, or simply curious about the dark side of fungi, read on to discover which mushrooms you should absolutely avoid.

1. Amanita phalloides (Death Cap)

Toxic Components: Amatoxins
Fatal Dose: As little as half a cap
Found In: Europe, North America, parts of Asia and Africa

The Amanita phalloides, better known as the Death Cap, is responsible for the majority of mushroom-related fatalities worldwide. Despite its innocent appearance—smooth greenish cap and white gills—it contains potent amatoxins that inhibit RNA polymerase, leading to liver and kidney failure. The Death Cap is particularly dangerous because it resembles edible species like the Paddy Straw Mushroom (Volvariella volvacea), especially in its immature “button” stage. Symptoms may not appear for 6–12 hours, often delaying treatment until it’s too late. Mortality rates range from 10–30%, even with medical intervention.

2. Amanita virosa (Destroying Angel)

Toxic Components: Amatoxins
Fatal Dose: One cap can be deadly
Found In: Europe and North America

Nicknamed the Destroying Angel, Amanita virosa looks deceptively pure with its all-white cap, gills, and stem. However, like the Death Cap, it contains lethal amatoxins that cause multi-organ failure if ingested. Symptoms mimic those of severe food poisoning: vomiting, diarrhea, abdominal cramps, followed by a deceptive recovery phase before liver and kidney damage sets in. If not treated aggressively, the Destroying Angel is often fatal.

3. Galerina marginata (Deadly Galerina)

Toxic Components: Amatoxins
Fatal Dose: As little as one mushroom
Found In: North America, Europe, Asia

The Deadly Galerina is a small, brown, wood-loving mushroom that often goes unnoticed—but its toxicity is anything but subtle. Containing the same amatoxins as the Death Cap and Destroying Angel, Galerina marginata is particularly dangerous to amateur foragers because of its resemblance to non-toxic “little brown mushrooms” (LBMs). It often grows on rotting logs and wood debris, a habitat shared by many edible varieties, increasing the risk of misidentification. Prompt medical treatment is critical to survival.

4. Cortinarius rubellus (Deadly Webcap)

Toxic Components: Orellanine
Fatal Dose: Varies; one cap can be enough
Found In: Europe and North America

One of the most insidious poisonous mushrooms, the Deadly Webcap contains orellanine, a toxin that causes delayed kidney failure. The latency period can be several days to two weeks, making it difficult to link symptoms to the mushroom. Cortinarius species often feature a rusty-brown spore print and a “webby” veil (cortina) between the cap and stem in young mushrooms. Unfortunately, this veil disappears as the mushroom matures, making identification challenging.

5. Cortinarius orellanus (Fool’s Webcap)

Toxic Components: Orellanine
Fatal Dose: One mushroom
Found In: Europe

Closely related to Cortinarius rubellus, the Fool’s Webcap is another silent killer. Its orellanine toxin accumulates in the kidneys and can cause irreversible renal failure. The lack of early symptoms makes this mushroom particularly dangerous. Despite its unassuming orange-brown color, the Fool’s Webcap has been mistaken for edible chanterelles—an error with often devastating consequences. There is no known antidote, and many victims require lifelong dialysis or kidney transplants.

6. Amanita muscaria (Fly Agaric)

Toxic Components: Muscimol, Ibotenic acid
Fatal Dose: Rarely fatal, but can be dangerous
Found In: Temperate regions of the Northern Hemisphere

The Fly Agaric is perhaps the most recognizable mushroom in the world, with its bright red cap speckled with white warts. While not usually deadly, it is psychoactive and toxic, especially when consumed in large quantities. Symptoms include nausea, hallucinations, muscle twitching, and delirium. Though deaths are rare, severe poisoning has occurred, especially among children or those mistaking it for edible species like Amanita caesarea. Its name comes from the historic practice of using it to kill flies by soaking it in milk.

7. Lepiota brunneoincarnata

Toxic Components: Amatoxins
Fatal Dose: One mushroom
Found In: Europe, North Africa, Middle East

This small, brownish mushroom resembles some edible parasol mushrooms but is highly toxic. Lepiota brunneoincarnata contains deadly amatoxins and has caused several fatalities across Europe and the Mediterranean. Its modest size and tendency to grow in grassy areas or gardens make it a dangerous find for amateur foragers, especially since its toxicity is not widely known outside of mycological circles.

8. Clitocybe dealbata (Ivory Funnel)

Toxic Components: Muscarine
Fatal Dose: Varies; rarely fatal
Found In: Europe and North America

The Ivory Funnel is a common lawn and pasture mushroom that poses a significant risk due to its high levels of muscarine—a compound that overstimulates the parasympathetic nervous system. Symptoms can begin within 30 minutes and include sweating, drooling, blurred vision, and difficulty breathing. While rarely fatal, severe poisoning can lead to respiratory failure if not treated promptly. It’s often mistaken for edible field mushrooms due to its pale appearance and small size.

9. Podostroma cornu-damae

Toxic Components: Trichothecene mycotoxins
Fatal Dose: Extremely low
Found In: Japan, Korea, China

Arguably one of the most grotesquely fascinating and deadly mushrooms, Podostroma cornu-damae is bright red and coral-shaped, resembling a fleshy horn or antler. Native to parts of Asia, it contains highly lethal trichothecene toxins. Ingestion has caused multiple deaths due to organ failure, hair loss, peeling skin, and lowered white blood cell counts. Even handling the fungus has reportedly caused skin irritation. It’s one of the few mushrooms that truly looks as dangerous as it is.

10. Omphalotus illudens (Jack-o’-Lantern Mushroom)

Toxic Components: Illudin S
Fatal Dose: Rarely fatal
Found In: North America

Despite its beautiful orange glow—sometimes literally, due to bioluminescence—the Jack-o’-Lantern Mushroom is not a treat. It’s often mistaken for edible chanterelles due to its color and gilled structure, but it contains illudin S, a toxin that causes severe gastrointestinal distress. While not usually deadly, poisoning leads to intense cramps, nausea, vomiting, and diarrhea that can last for hours. Its bright hue should be a warning, but even seasoned foragers have fallen for its deceptive looks.