naturebriefs
8:52in productionCh. 1 · Type of Death/ 8:52 · ceiling 15 min
Fungi

Amanita phalloides

The deadliest mushroom on Earth doesn’t need to be rare, flashy or hard to mistake — it just needs to be eaten once.

Amanita phalloides is a European fungus now found worldwide. It forms symbiotic relationships with broadleaved trees. It produces α-amanitin — a thermostable toxin that inhibits RNA polymerase II in humans, causing fatal organ failure. Its own RNA polymerase is resistant. It is responsible for 90% of annual mushroom-related deaths. Half a fruiting body is lethal. Its toxin is now used in targeted cancer therapies.

FungiDiseaseEvolutionEcologyDisease across the network →
Chapters & takeaways4
  1. 0:54
    Type of Death

    It is the deadliest mushroom known — and the defining species of all deadly Amanitas.

  2. 2:27
    Lethal Dose

    Half a cap kills. It causes 90% of global mushroom fatalities. Its toxin destroys liver and kidney function.

  3. 3:57
    How It Kills Without Killing Itself

    Its poison survives cooking. It blocks RNA synthesis in humans — but not in itself.

  4. 5:24
    From Poison to Payload

    α-Amanitin is both a fatal toxin and a precision cancer drug — because it targets RNA polymerase II with absolute specificity.

Worth your time?

Yes. See the whole thing.

4.5/ 5
What works
  • ectomycorrhizal symbioses with broadleaved trees
  • RNA polymerase insensitivity to its own amatoxins
What does not
  • taste bitter
  • bruise blue
  • smell foul
  • change colour when cut or cooked
See it if
  • broadleaved trees
Skip it if
  • humans
  • foragers who cannot distinguish it from edible Amanita species
The written brief1 min read

What the species is and where it came from

Amanita phalloides is a basidiomycete fungus native to Europe. It is now globally introduced.

How it works, in terms someone would actually use

It delivers α-amanitin — a thermostable toxin — that halts RNA polymerase II in human cells. Cooking or freezing does not reduce its effect. Half a fruiting body kills an adult.

What it gets right

It establishes ectomycorrhizal symbioses with broadleaved trees. Its RNA polymerase is insensitive to its own amatoxins — so it avoids autotoxicity.

What it does not

It does not warn. It does not taste bitter. It does not bruise blue. It does not smell foul. It does not change colour when cut or cooked.

What it changed

It enabled oncological repurposing: α-amanitin is now used as a payload in antibody-drug conjugates targeting cancer cells, including multiple myeloma and solid tumours.

Who it is for, and who it is not

It is for broadleaved trees. It is not for humans. It is not for foragers who cannot distinguish it from edible Amanita species.

Is it worth your time

Yes, if you forage for mushrooms in Europe or any region where it has been introduced. No, if you do not handle wild fungi. It is not worth seeking out; it is worth avoiding.

Same habitat · Fungi4 of 15
7:57
NidulariaceaeNidulariaceae are saprobic fungi in the order Agaricales, cosmopolitan and found on decaying wood and mulched soils. Five genera are distinguished by morphology and peridiole structure. Their spores develop internally in gasteroid fruiting bodies and are dispersed by rain-splash — not springs — sometimes aided by funicular cords. Taxonomy has shifted from historical description to DNA-guided phylogeny. First mentioned by Clusius in 1601; Paulet’s 1790–1793 spring hypothesis was incorrect.
9:11
Fairy ringFairy rings are fungal growth patterns—not organisms—that reveal radial digestion and nutrient exhaustion in soils. They occur in forests, grasslands, and rangelands. Verified mechanisms include enzymatic breakdown at hyphal tips and central dieback. No lifespan, species, toxicity, or ecological impact beyond grass discoloration is stated. Folklore is noted but not endorsed.
10:22
MorchellaMorchella is a genus of edible sac fungi in the order Pezizales (division Ascomycota), typified by Morchella esculenta in 1794. It exhibits a distinctive honeycomb cap morphology due to ridges and pits, and comprises over seventy molecularly supported species worldwide, most showing high continental endemism and provincialism. The genus is under active phylogenetic, biogeographical, taxonomic, and nomenclatural study, with new species recently described across multiple continents. Morels are highly valued in gourmet cuisine—especially Catalan and French—but are toxic when raw or undercooked. Commercial harvesting of wild morels constitutes a multimillion-dollar industry across the temperate Northern Hemisphere, including North America, Turkey, China, the Himalayas, India, and Pakistan. Their ecology remains poorly understood, though many species associate with trees symbiotically or saprotrophically, and some exhibit pyrophilic behavior, fruiting abundantly after wildfires. Cultivation has historically been difficult, though recent breakthroughs—including indoor cultivation using grass and climate control—have achieved reliable fruiting. Toxicity concerns include thermolabile hydrazine-based mycotoxins neutralized by cooking, and risks from environmental contaminants like lead and arsenic in certain habitats.
8:46
PleurotusPleurotus is a genus of gilled mushrooms. It includes some of the most commonly cultivated edible mushrooms in the world. Some species have been used in the mycoremediation of pollutants. The caps may be laterally attached (with no stipe). If there is a stipe, it is normally eccentric and the gills are decurrent along it. The spores are smooth and elongated (described as "cylindrical"). Where hyphae meet, they are joined by clamp connections. Pleurotus is not considered to be a bracket fungus, and most of the species are monomitic (with a soft consistency). However, remarkably, P. dryinus can sometimes be dimitic, meaning that it has additional skeletal hyphae, which give it a tougher consistency like bracket fungi.
Up next in Nature

Devils Tower

1906 · 9:38

A tower that sheds itself — every fallen column is proof it is still alive.

Play nextBack to Fungi
9:38