Death Cap
Deadly| Scientific name | Amanita phalloides |
| Family | Amanitaceae |
| Portuguese name | Cicuta-verde, Chapéu-da-morte, Rebenta-bois |
| English name | Death cap |
| Season | September, October, November, December |
| Habitat | Oak forest, Cork oak, Chestnut forest, Mixed forest |
| Look-alikes | Field Mushroom, Caesar's Mushroom, Russula virescens |
Description
Amanita phalloides (death cap) is the deadliest mushroom in the world, responsible for over 90% of all fatal mushroom poisonings in Europe. It is widespread throughout Portugal. The fruiting body is medium to large, with a characteristic pale green or olive cap, white gills, and a sac-like volva at the base of the stem.
Cap
- Diameter: 5–15 cm
- Shape: hemispherical when young, later convex to flattened
- Colour: pale green to olive-yellow, sometimes almost white. Uneven colouration with radial fibres
- Surface: smooth, slightly sticky in wet weather
- Margin: smooth, without striations
Stem
- Height: 8–15 cm
- Width: 1–2.5 cm
- Colour: white or with a faint greenish tinge
- Ring: white, membranous, in the upper part of the stem
- Volva: sac-like, white, at the base of the stem — key identifying feature. Often hidden in the soil
- Surface: with a moiré (zigzag) pattern
Flesh
- Colour: white, no colour change when cut
- Smell: faint and neutral in young specimens; unpleasant and sickly sweet in older ones (described as “honey-like” or “rose-like”)
- Taste: pleasant, which makes this mushroom particularly dangerous — poisoning occurs unnoticed
Spore print
White.
Toxicity
Toxins
- Amatoxins (primarily α-amanitin) — heat-stable, not destroyed by boiling, frying, drying, pickling, or freezing
- Phallotoxins — damage hepatocyte membranes
- Virotoxins — less significant, poorly absorbed from the GI tract
Mechanism of action: α-amanitin inhibits RNA polymerase II, blocking mRNA synthesis. This halts protein production and leads to cell death. Primary target — the liver (hepatocytes); kidneys are also affected.
Phases of poisoning
| Phase | Time | Symptoms |
|---|---|---|
| 1. Latent | 6–24 h | Asymptomatic. Toxins are already being absorbed |
| 2. Gastrointestinal | 6–24 h | Sudden severe vomiting, profuse watery diarrhoea, abdominal cramps, dehydration |
| 3. False recovery | 24–72 h | Symptoms subside. Patient feels better, but toxins continue destroying the liver |
| 4. Liver failure | 3–5 days | Jaundice, coagulopathy, encephalopathy, multi-organ failure |
Mortality: 10–20% with modern treatment. Without treatment — up to 50–90%. In fatal cases, death occurs within 7–10 days.
Treatment
There is no specific antidote. Treatment is supportive:
- Activated charcoal (if early presentation)
- N-acetylcysteine (liver protection)
- Penicillin G in high doses (competes with hepatic uptake of amatoxins)
- Silibinin (hepatoprotective)
- For fulminant liver failure — liver transplantation
In 2023, researchers (Nature Communications) discovered a potential antidote — indocyanine green (ICG), an STT3B inhibitor that doubled survival rates in mouse experiments, though it remains at the research stage.
Where and when
Season
- Main season: October–December
- Onset: sometimes from late September, after the first autumn rains
- Mass fruiting after warm, abundant rains
Habitats in Portugal
- Throughout the country, from north to south, coast to interior
- Oak forests — under holm oak (Quercus ilex), cork oak (Quercus suber)
- Chestnut forests — especially in Trás-os-Montes
- Mixed forests — with beech, hornbeam
- Parks and gardens — may appear in cultivated landscapes with imported trees
- Forms ectomycorrhiza with broadleaf trees
Ecology
The species continues to expand its range — it has been introduced to Australia, North and South America, and South Africa via tree saplings.
Look-alikes
Common confusions
| Species | Difference from death cap |
|---|---|
| Field mushroom (Agaricus campestris) | Gills pink → brown (not white!). No volva |
| Caesar’s mushroom (Amanita caesarea) | Gills and stem yellow (not white). More vivid orange cap |
| Green-cracking russula (Russula virescens) | No ring or volva. Brittle gills. Cap with fine cracks |
| Paddy straw mushroom (Volvariella volvacea) | Pink gills when mature. Common cause of poisoning in Asian communities |
| False death cap (Amanita citrina) | Smell of raw potatoes. Volva closely attached, not sac-like |
Safety rule
Always dig up the entire mushroom — the volva may be hidden underground. The volva is the key distinguishing feature of the death cap.
Poisoning cases in Portugal
- According to CIAV, the death cap is the cause of most severe mushroom poisonings in Portugal
- Immigrants and tourists are at greatest risk, confusing local species with mushrooms from their home countries
- According to a study in Acta Medica Portuguesa (1990–2008): of 93 mushroom poisoning cases, 63.4% involved hepatotoxic syndrome (amatoxins), with a mortality rate of 11.8%
Image sources
- amanita-phalloides.webp — Death cap (Amanita phalloides) — deadly poisonous mushroom. Author: Archenzo. License: CC BY-SA 3.0. Source
See Also
Habitats:
Related articles:
Sources
- Wang Q. et al. — Identification of indocyanine green as a STT3B inhibitor against mushroom α-amanitin cytotoxicity // Nature Communications, 2023
- Brandão J.L. et al. — Intoxicação por cogumelos em Portugal // Acta Medica Portuguesa, 2011
- Garcia J. et al. — Amatoxins and phallotoxins in Amanita phalloides from northeastern Portugal // Toxicology, 2015
- CIAV — Centro de Informação Antivenenos, INEM Portugal
- Museu Virtual da Biodiversidade — Universidade de Évora
- BioDiversity4All / GBIF Portugal — species records
- Sociedade Portuguesa de Micologia
Disclaimer: Identifying mushrooms from descriptions and photographs on the internet is not a substitute for consulting an experienced mycologist. The authors assume no responsibility for the consequences of collecting and consuming mushrooms. If you suspect mushroom poisoning, call 112 immediately.
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