Poisonous Lawn Mushroom Types: 6 to Know in the US

A handful of species cause most of the trouble on American lawns. Learning these does not qualify anyone to eat anything; it tells you which discoveries in your own yard deserve a phone call rather than a shrug.

• [Chlorophyllum molybdites](/lookup/toxic-mushrooms/chlorophyllum-molybdites), green-spored parasol. Large, pale, brown-scaled cap, free gills white ageing to dull green, stem ring, green spore print. Described as one of the most common lawn and pasture mushrooms in the country outside the Pacific Northwest, and as the most frequently eaten poisonous mushroom in North America. Vomiting, diarrhoea and colic start one to three hours after eating and can be severe, particularly in children.
• [Amanita bisporigera](/lookup/toxic-mushrooms/amanita-bisporigera) and [Amanita ocreata](/lookup/toxic-mushrooms/amanita-ocreata), destroying angels; [Amanita phalloides](/lookup/toxic-mushrooms/amanita-phalloides), death cap. White or pale, free white gills, stem ring, cup-like volva below soil level. Amatoxins destroy liver tissue. Poison Control states that the most toxic mushrooms may be growing in your own yard and that a few bites can cause fatal liver damage.
• [Galerina marginata](/lookup/toxic-mushrooms/galerina-marginata). Small, tawny, ringed stem, rusty spore print, clustered on buried wood. Also amatoxins.
• [Clitocybe dealbata](/lookup/toxic-mushrooms/clitocybe-dealbata), ivory funnel. Dull white to grey-pink, decurrent gills running down the stem, in the same lawns and rings as harmless-looking tan mushrooms. Contains muscarine.
• [Omphalotus illudens](/lookup/toxic-mushrooms/omphalotus-illudens), jack-o'-lantern. Bright orange clusters on wood, gills running down the stem, weakly bioluminescent. Illudin toxins; severe cramps and diarrhoea.
• Scleroderma earthballs. Thick warty skin, purple-black inside, listed among genera that can be lethal to dogs.

Feeling fine an hour later proves nothing, and feeling terrible quickly is not the worst outcome. The timing pattern is roughly:

• Within 30 minutes to 2 hours. Muscarine species such as Clitocybe and Inocybe: sweating, salivation, tears, blurred vision, slow heart rate. Unpleasant and sometimes serious, but the onset is fast enough that treatment usually starts early.
• 1 to 3 hours. Green-spored parasol: severe vomiting, diarrhoea and colic. Cases can be severe, particularly in children, and deaths have occurred, though they are described as incredibly rare.
• 5 to 10 hours. Sulphur tuft: reports describe delayed diarrhoea, nausea, vomiting and collapse.
• 6 to 12 hours or longer. Amatoxins. The North American Mycological Association describes a 6 to 12 hour or longer delay before severe gastrointestinal distress in amatoxin poisoning. What follows is the dangerous part: an apparent recovery, then liver failure.
• Hours to days later, on drinking alcohol. Coprine in the common ink cap blocks the enzyme that clears acetaldehyde, producing flushing, nausea, vomiting, headache, a racing heart and a drop in blood pressure.

The practical rule: the time to call is when the mushroom was eaten, not when symptoms arrive.

• The stem base. Dig it out whole. A membranous cup or sac below soil level is the Amanita volva, and it is the single most important observation on a lawn. It breaks off easily and is invisible once you snap the stem.
• Gill colour at maturity, not on the day. White ageing to dull green is the green-spored parasol. Yellow darkening to green is sulphur tuft. Pink darkening to chocolate brown is Agaricus. White staying white on a ringed stem is the pattern to worry about.
• Spore print. Green means Chlorophyllum molybdites, described as the only large mushroom producing a green spore print. Rusty brown on a wood-growing cluster raises Galerina.
• Soil or wood. Amatoxin-containing Galerina grows on wood; the deadly Amanitas grow from soil near host trees.

Every one of these takes seconds. Together they are what a poison specialist and a mycologist will reconstruct from your photographs, which is why taking them before you bin the mushroom matters.

Searches for edible yard mushrooms are common, and the honest answer is that this site does not answer them. Poison Control's guidance is unambiguous: eating any amount of any wild mushroom can be very dangerous, mushrooms that look alike can be very different, and only experts in mushroom identification can tell poisonous species from safe ones.

A photograph is not certainty. Neither is an app, including this one. Photograph it and the app identifies it, and that is where its job ends.

If you want to learn wild mushrooms properly, work with a local mycological society, in person, with specimens in hand.

• Call immediately, before symptoms. In the United States, Poison Control is 1-800-222-1222. The service is free, confidential and available 24 hours a day, and poison specialists work with mycologists to identify the mushroom and with hospital staff on treatment.
• Keep a specimen. A whole mushroom with the base intact, in a paper bag, not plastic and not sealed. If several were growing together, take two or three at different ages.
• Note the substrate and location. Soil or wood, near which tree, and how many were present.
• For dogs and cats, call your veterinarian or ASPCA Animal Poison Control at (888) 426-4435. The North American Mycological Association notes that dogs take a special interest in Amanita phalloides and Inocybe species, possibly because of their fishy odour, and advises collecting samples in paper bags or waxed paper and refrigerating them until examination.
• Do not induce vomiting on your own initiative. Let the poison centre or the vet decide.
• Do not wait out the delay. With amatoxin species the gap before symptoms can exceed 12 hours, and treatment works best before liver injury is established.

Prevention, in practice, is a walk of the yard before children or dogs go out, described on dog ate a mushroom in the yard.