Most poisonous mushrooms don't look sinister. They look like the ones in the supermarket, or the ones in the foraging book, or the ones a friend picked last year. That is the whole problem. This guide covers the species that most often cause serious poisonings in the US, the edibles they are mistaken for, and what to do if the worst happens. The rule behind all of it: never eat a wild mushroom unless its identity has been confirmed by an experienced local expert, in person.
Why lookalikes are so dangerous: delayed symptoms
With most food poisoning, you feel ill quickly and you know what caused it. The deadliest mushrooms don't work that way.
- Amatoxins (in the death cap, destroying angels and deadly galerina) usually cause no symptoms for 6 to 24 hours. Then come severe vomiting, diarrhea and stomach pain, sometimes followed by a period where the person seems to recover while liver damage continues. Cooking, freezing and drying do not destroy these toxins.
- Orellanine (in some webcaps, Cortinarius species) can take from a couple of days to two or three weeks to cause symptoms, by which time the kidneys may be badly damaged.
- Gyromitrin (in false morels) typically causes symptoms 6 to 12 hours later and can damage the liver and nervous system.
By the time someone feels ill, the meal is long forgotten, which is why early medical advice saves lives.
The death cap
The death cap (Amanita phalloides) is responsible for a large share of fatal mushroom poisonings worldwide.
- Cap: smooth, usually olive-green to yellowish green, sometimes pale or almost white, up to around 15 cm (6 in) across.
- Gills: white, crowded, and free of the stem. They stay white as the mushroom ages.
- Stem: white, often with faint greenish markings, with a thin, skirt-like ring near the top (it can fall off).
- Base: a loose, white, sack-like cup (the volva) around a swollen base. It is often buried, so it gets left behind when a mushroom is snapped off.
- Where: not native to the US, but now established, mostly with oaks (including live oaks) in coastal California, and also found in parts of the Northeast and mid-Atlantic. In California it fruits mainly in fall and winter.
People mistake it for field mushrooms, for puffballs when it is still a round "egg", for green or yellow edible species they know from elsewhere, and in particular for the paddy straw mushroom, which is familiar to many people from Southeast Asia.
Destroying angels
Destroying angels are pure white Amanitas with the same deadly toxins as the death cap. The US has several species, including the eastern destroying angel (Amanita bisporigera) in Eastern woodlands and Amanita ocreata in California oak woodland.
Everything about them is white: cap, gills, stem, ring and volva. They are mistaken for button, field and horse mushrooms and, at the egg stage, for puffballs. Two quick checks rule out many mix-ups, though never all of them: edible Agaricus mushrooms have pink to chocolate-brown gills and no volva, and a true puffball is pure white and featureless inside when cut top to bottom, with no outline of a cap and gills.
Regional killers to know
Deadly galerina
The deadly galerina (Galerina marginata) is a small brown mushroom on rotting wood, with rusty-brown gills and, when fresh, a thin ring on a slender stem. It contains the same toxins as the death cap. It is most often mistaken for honey mushrooms (Armillaria), which also grow on wood, sometimes right alongside it. Honey mushrooms grow in dense clusters, are usually larger and stockier, and have whitish to cream gills. Small brown mushrooms on wood are strictly for experts.
False morels
False morels (Gyromitra species) have reddish-brown caps of brain-like or saddle-shaped folds, not the pitted honeycomb of a true morel, and are chambered or stuffed with cottony tissue inside. They fruit in spring, often in conifer forests, right when morel hunters are out. Also watch for Verpa species, whose cap hangs from the very top of a cotton-filled stem like a thimble. A true morel is hollow from the tip of the cap to the base of the stem, with the cap joined to the stem (in half-free morels, about halfway up the cap).
Jack-o'-lantern
The jack-o'-lantern (Omphalotus illudens in the East, with related species in the West) is bright orange and grows in tight clusters on wood or from buried roots, often at the base of hardwood stumps. It has true, sharp-edged gills that run down the stem, and orange flesh inside. It causes severe vomiting, cramps and diarrhea. Chanterelles grow singly or scattered from the soil, with blunt, forked ridges and paler flesh. See our chanterelle identification guide.
False parasol
The false parasol (Chlorophyllum molybdites) is widely described as the poisonous mushroom most often eaten in North America. It is large and white with brownish scales, grows on lawns, in parks and pastures, often in rings, from summer to fall across much of the country (less so in the Pacific Northwest). Its gills start white and turn grayish-green as it matures, so young specimens are easy to mistake for edible parasols and shaggy parasols. It causes severe vomiting and diarrhea, usually within 1 to 3 hours.
Lookalike table
| Poisonous species | Mistaken for | Key differences | Where found (US) |
|---|---|---|---|
| Death cap | Paddy straw mushroom, puffballs (egg stage), meadow mushrooms | White gills, ring, sack-like volva at the base | Mainly with oaks in coastal California; also parts of the Northeast and mid-Atlantic |
| Destroying angels | Meadow and button mushrooms, puffballs | All white, white gills, ring, volva | Eastern woodlands; California oak woodland |
| Deadly galerina | Honey mushrooms | Small, rusty-brown gills, thin stem | Rotting wood, widespread |
| False morels | Morels | Brain-like folds, chambered or cottony inside | Spring, often conifer forests |
| Jack-o'-lantern | Chanterelles | Sharp true gills, clusters on wood, orange flesh | Base of hardwood stumps, buried roots |
| False parasol | Parasol, shaggy parasol | Gills turn grayish-green, grows on lawns | Lawns, parks, pastures; widespread except the Northwest |
Myths that put people in hospital
None of these "tests" work. Every one of them has been followed by a poisoning:
- "If it peels, it's safe." The death cap peels easily.
- "Silver or garlic turns black near poison." It doesn't.
- "Animals or slugs eat it, so it's fine." Slugs, rabbits and other animals can eat mushrooms that are deadly to people.
- "Cooking or boiling removes toxins." Not the deadly ones.
- "It smells and tastes nice." Survivors of death cap poisoning have reported that it tasted good.
- "Mushrooms on wood are all safe." The deadly galerina grows on wood.
- "The app said it was edible." Photo apps are a starting point for learning, not a safety check.
If someone may have eaten a poisonous mushroom
- Call Poison Control at 1-800-222-1222. It is free, confidential, open 24 hours a day, and connects you to your local poison center. Call even if the person feels fine: the deadliest species cause no symptoms for hours.
- Call 911 if the person is unconscious, having a seizure, struggling to breathe or collapsed.
- Don't try to make them vomit unless a poison specialist tells you to.
- Keep the evidence. Put any leftover mushrooms, raw or cooked, plus trimmings, in a paper bag (not plastic), and photograph them. Poison centers may be able to arrange for an experienced identifier to look at them.
- Note the details: what was eaten, how much, when, and who else shared the meal. Everyone who ate it needs advice, and pets that ate wild mushrooms need a vet.
The short version
- The death cap and destroying angels kill more foragers than anything else, and cooking does not make them safe.
- Always check the gills, ring and base, and dig up the whole base to look for a volva.
- Deadly galerina, false morels, jack-o'-lanterns and false parasols are the other US species to know on sight.
- No myth or kitchen test can tell you a mushroom is safe.
- Never eat a wild mushroom unless an experienced local expert has confirmed it. If you're new, start with our mushroom foraging for beginners guide and check the foraging calendar for when these species fruit near you.
- If you want gourmet mushrooms with no identification risk at all, grow them: see the easiest mushrooms to grow at home.