False Morel Poisoning

Medically Reviewed by Dany Paul Baby, MD on November 04, 2022
Written by Alyssa Anderson
6 min read

Mushroom hunting is a fantastic way to get outside and explore the natural world. But this hobby can be dangerous — and even deadly — if you don’t know your mushrooms. Lots of popular mushrooms — like morels — have dangerous look-alikes — like false morels. 

Before going on a mushroom hunt, make sure you know how to identify false morels. This knowledge could be the difference between a successful foraging trip and one that ends in false morel poisoning.

The term false morel is used to describe a handful of mushroom species. Mushrooms aren’t plants or animals. Instead, they’re members of a distinct group of organisms called fungi. 

All species of false morels — and all mushrooms in general — have a few key parts: 

  • Mycelium. This is an extensive, rootlike network that stretches throughout the ground. It's the perennial part of the mushroom. It works to collect and store nutrients from the decaying material that it grows on. 
  • Fruiting bodies. This is the above-ground part of the mushroom that everyone is most familiar with. The mycelium produces fruiting bodies at certain times of the year in order to help the fungi reproduce. Most — including false morels — have stems that come out of the ground with textured caps on top. 
  • Spores. These are very small structures that are made and dispersed by the fruiting bodies. They float through the air and sprout into new mushrooms when they land in favorable environments. 

When people talk about false morels, they’re referring to one of three species: 

  • Gyromitra esculenta — this specific species is most commonly referred to as a false morel 
  • Verpa bohemica
  • Verpa conica

All of these species look like morels, grow in similar habitats, and contain the same poisonous toxin.

False morels are much more poisonous than normal morels. This means that your health depends on your ability to correctly identify these mushrooms. 

The only part of these mushrooms that you’ll likely recognize is their fruiting bodies. The three main species of false morels don’t look exactly alike. Learn to identify each of them by sight. 

Identifying details to focus on for G. esculenta include its dark brown or reddish cap and solid white stalk. It has textured ridges across its cap, with gentle, smooth-looking pits in between.  

V. bohemica and V. conica both have fruiting bodies with yellow caps and white stalks. V. bohemica’s cap has defined ridges that can have a gray hue, and V. conica has a mostly smooth cap.  

All three species grow across the northern U.S. Their concentrations tend to decrease toward the drier Midwestern regions. G. esculenta, for example, thrives in mixed forests. It grows well in areas with: 

  • Oaks
  • Maples
  • Douglas firs 

Most false morels produce their fruiting bodies in the spring. At all other times, they only consist of their buried mycelial networks.

All species of false morels contain a poisonous neurotoxin called gyromitrin. This affects your body’s mucus membranes and digestive system. It can lead to widespread problems throughout your body, but most cases cause symptoms that resemble a bad stomach flu. 

False morels are poisonous both through consumption and through inhalation. Heating removes the neurotoxin from these mushrooms and turns it into a gaseous form. This means that if you cook false morels in a small, poorly ventilated space, you can inhale enough neurotoxin to get sick. 

Technically, if you cook them safely and thoroughly, you can remove all of the neurotoxins from false morels. This would make them safe to eat. But even slightly undercooking the mushrooms can leave enough neurotoxin to get you sick. Be on the safe side — never cook or eat false morels.  

Not every false morel contains the same amount of this neurotoxin. The exact amount depends on factors like the species and the mushroom’s environment.

False morel poisoning is the result of consuming enough gyromitrin to cause symptoms. Symptoms can differ greatly from person to person. Some people can eat them and not feel any symptoms at all. Others become violently ill. 

Symptoms typically set in six to 24 hours after you’ve eaten the false morels. You’ll likely experience symptoms sooner if you inhale the toxin when cooking. 

Common symptoms include: 

These symptoms will last until the toxin has left your body. This may be as short as a few hours but could take longer. 

In the most severe cases, symptoms can progress much further. This can lead to complications like: 

You can eat enough of the neurotoxin in false morels to kill you — but it would take a high concentration in a lot of mushrooms. For children, the lethal dosage of gyromitrin is 10 to 30 milligrams per kilogram of body weight. This increases to 20 to 50 milligrams per kilogram in adults.

If you’ve just gone mushroom hunting and are about to cook up your mushrooms — stop. There are a few simple steps that you should always take before eating a wild mushroom. Make sure to:  

  • Take a picture of the mushroom
  • Put one example of the mushroom variety in the fridge in a bag labeled “do not eat” 
  • After cooking and eating the remaining mushrooms, pay attention to how you feel for the next 24 hours — the mushrooms are most likely safe if you haven’t felt any symptoms within this time frame
  • Only throw away the saved mushroom when you’re sure that there aren’t any negative side effects 

If you do experience negative side effects after cooking or eating any mushroom, then you need to immediately contact poison control. Poison control can use the picture and saved mushroom to accurately figure out what species you ate. They know which experts to contact in tricky cases. 

Even if your symptoms seem mild at first, you still need to contact poison control. Moderate to severe cases of false morel poisoning require you to take action as soon as possible to keep your symptoms from getting worse. 

An expert might recommend that you take a single dose of charcoal if your symptoms are just beginning. In the most severe cases, you’ll need a strong dose of vitamin B6 to help counteract the effects of the neurotoxin. You may or may not need to seek immediate medical attention. 

Poison control can evaluate your symptoms and approximate dosage and tell you what next steps are best for your situation. The best general advice for every case of false morel poisoning is to stay as hydrated and well-nourished as possible. This will aid your recovery process.

Morel mushrooms are the relatively safe look-alikes that give false morels their name. Morels are one of the most prized and popular treats for both experts and beginners. There are a few different species of morel mushrooms. Some are yellow, others are black. 

Like false morels, they also grow in moist, mixed forest habitats and are most common in the spring. 

There are a few key details to pay attention to in order to distinguish true morels vs. false morels. Morels have much deeper pits and more well-defined ridges on their caps than false morels. They also have smooth, hollow stems when you cut them down the middle. False morels have fibrous, full stems. 

Even morels can cause stomach irritation if you don't cook them properly. Always make sure that you know what you’re doing when it comes to the art of mushroom hunting. Dangers lurk around every corner, and you don’t want to end up poisoning yourself, your friends, or your family.