PHOTO: Mushroom in the lawn in front of a house.

Are You Really Going to Eat Those Mushrooms?

I don’t have to look outside to know that it has been raining lately. My phone has been ringing off the hook with calls from the Illinois Poison Center requesting help with potential mushroom poisoning cases. I helped with four different cases today! Three of them involved children; the other was a case of an adult eating something that “looked good to eat.”

Chlorophyllum molybdites, the green-spored lepiota, was the mushroom du jour. Three of the cases involved this toxic mushroom that is commonly found in yards after summer rains. It looks lovely, and it usually won’t kill you, but I’m told that it makes one sick enough that people think that they might die. Symptoms involve vomiting and/or diarrhea, often severe, starting one to three hours after ingestion. This is the most commonly eaten toxic mushroom in the United States.

PHOTO: Suburban lawn covered with mushrooms.
It might seem like a bumper crop of free eats in your lawn, but Chlorophyllum molybdites is toxic.

Today’s other culprit was Panaeolina foenisecii, known as the lawn mower’s mushroom, also commonly found growing in lawns. Unlike Chlorophyllum molybdites, this is no beauty. It is an LBM (little brown mushroom). It too can cause gastric upset and has been reported to cause slight hallucinations in some cases, but never in the numerous cases in which I’ve been involved.

PHOTO: Panaeolus foenisecii, or lawn mower's mushroom
Panaeolus foenisecii, or lawn mower’s mushroom, is also nonedible. (Photo with permission Michael Kuo,

Not all mushrooms growing in lawns are toxic. But the only way to tell is to know what the mushroom is (identify it). There are no short cuts or tricks to knowing whether a mushroom is toxic or not, so think before you eat! There are a number of mushroom books that can help (I’m partial to Wild Edible Mushrooms of Illinois and Surrounding States by my colleague Joe McFarland and me). And a great way to learn mushroom identification is to join a club like the Illinois Mycological Association.

Identifying mushrooms and plants for the Illinois Poison Center and hospitals is something that I and other Chicago Botanic Garden staff gladly do. Freely sharing our expertise is part of the Garden’s commitment to the region.

©2014 Chicago Botanic Garden and

Published by

Greg Mueller

Gregory M. Mueller, Ph.D., serves as the Negaunee Foundation Vice President of Science at the Chicago Botanic Garden. Before joining the Garden, Dr. Mueller worked for 23 years at the Field Museum as curator of mycology in the Department of Botany. He was chair of the Field Museum's Department of Botany from 1996 to 2005. Mueller received his B.A. and M.S. from Southern Illinois University, Carbondale, and his Ph.D. from the University of Tennessee.

3 thoughts on “Are You Really Going to Eat Those Mushrooms?”

  1. I heard from a Lithuanian friend that she and her family used to gather mushrooms from the forest and stew them in water with a silver dollar. If the silver turned black, they knew they had a toxic mushroom and they threw out the entire batch.

    1. Kate,

      Unfortunately, none of the easy folk identification tricks work. Boiling a mushroom with a silver dollar won’t tell you if something is toxic or not. Nor will watching animals to see what they eat since some animals can eat deadly toxic mushrooms or believing that all mushrooms growing on wood are edible (the deadly Galerina grows on wood in many parts of the US, including the Chicago region). The only way to know is to identify the mushroom and know its edibility. If you aren’t sure what it is, and know that that species is edible, DON”T eat it.


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