Poisonous Mushrooms in Oklahoma: Risks, Symptoms, and Prevention
Mushrooms are a fascinating part of Oklahoma’s natural ecosystem, providing culinary and medicinal benefits for those who know how to properly identify them. However, not all mushrooms are safe to consume. Some contain potent toxins that can cause severe illness or even death in humans and pets. It is important to note that there are no known mushrooms in the United States that are poisonous to the touch—a toxic mushroom can only harm you if eaten.
It's important to note that mushroom species can be location-specific, and it's always important to reference a local mushroom guide or expert to ensure you can properly identify the mushroom. A great way to learn about mushrooms safely is by foraging with experienced individuals. Going out with a group of mushroom foragers can help you correctly identify edible and toxic species. I offer free and private guided mushroom identification forays providing an excellent opportunity to gain hands-on experience in a safe and educational setting.
Current Status of Mushroom Poisonings in the United States
The Centers for Disease Control and Prevention (CDC) and Poison Control Centers across the U.S. receive thousands of calls annually about potential mushroom poisonings. According to a study published by the National Center for Biotechnology Information (NCBI), most reported mushroom poisonings occur due to misidentification of toxic species, particularly by beginner or amateur foragers. The study highlights that over 1,300 cases of mushroom poisoning were reported in a single year, with varying symptoms depending on the species consumed.
The Most Common Toxic Mushrooms in Oklahoma
Chlorophyllum Molybdites (The Vomiter)
This is the #1 mushroom species I get asked about in the spring and summer. This species is the most common toxic mushroom found in Oklahoma. It also causes the most hospital visits for small children and pets. Known as the vomiter mushroom, this species is the leading cause of mushroom poisoning in North America. It causes severe gastrointestinal distress within hours of ingestion but is not typically fatal. These mushrooms resemble edible parasol mushrooms, leading to frequent misidentification.
Where They Grow: These mushrooms thrive in lawns, pastures, and grassy areas, often appearing in fairy rings after heavy rain.
Gyromitra Caroliniana (False Morel)
The Gyromitra genus includes several species commonly referred to as false morels, which are known to contain gyromitrin, a toxin that breaks down into monomethylhydrazine (MMH)—a chemical also found in rocket fuel. Gyromitrin can cause severe poisoning, leading to vomiting, diarrhea, dizziness, seizures, and in extreme cases, organ failure.
False morels can be mistaken for true morels (Morchella spp.), but they differ in their irregularly wrinkled or lobed caps, rather than the uniform honeycomb structure of true morels. Gyromitra caroliniana and Gyromitra brunnea, which are suspected to be toxic, but no official research has been done at any of the state universities. While some people have consumed false morels after prolonged cooking, this practice is extremely risky as toxins may not be fully neutralized. It is strongly advised to avoid consuming any false morels until further research by scientists.
Where They Grow: False morels are typically found in moist wooded areas, near rotting logs, or along riverbanks, especially in spring.
Death Cap (Amanita genus)
The Amanita genus includes some of the deadliest mushrooms in the world, such as the Death Cap (Amanita phalloides) and the Destroying Angel (Amanita bisporigera). These mushrooms contain amatoxins, which cause irreversible liver and kidney damage. Symptoms may take 6-12 hours to appear, starting with nausea, vomiting, and diarrhea, eventually leading to organ failure if untreated.
Where They Grow: Amanitas are commonly found in forests and woodlands, growing near oak and pine trees. They often emerge from the soil, sometimes with a visible sac-like structure at their base.
Galerina Marginata (Funeral Bell)
Mushrooms in the Galerina genus are often confused for Psilocybe, and unfortunately, mushroom foragers looking for psychoactive mushrooms end up finding toxic ones. These small brown mushrooms contain amatoxins similar to Amanita species, making them just as deadly. They are commonly found on rotting wood and should be avoided at all costs. Often mistaken for edible mushrooms like Psilocybe, these small brown mushrooms contain amatoxins similar to Amanita species, making them just as deadly. They are commonly found on rotting wood and should be avoided at all costs.
Where They Grow: These mushrooms grow on decaying wood, logs, and forest debris, often in damp areas.
Inocybe and Clitocybe Species
Mushrooms in the Inocybe and Clitocybe genera contain muscarine, a compound that affects the nervous system. Inocybe fastigiata and Inocybe geophylla are two species commonly found in Oklahoma that produce muscarine poisoning. Similarly, Clitocybe dealbata and Clitocybe rivulosa, also known as the sweating mushrooms, are highly toxic and grow in grassy areas. Symptoms of muscarine poisoning include excessive salivation, sweating, blurred vision, abdominal cramps, nausea, vomiting, diarrhea, and difficulty breathing. In severe cases, muscarine poisoning can lead to respiratory failure and death if untreated. Immediate medical attention is required if ingestion is suspected.
Where They Grow: These mushrooms are commonly found in woodlands, grassy meadows, and along pathways, often growing in clusters.
How Mushroom Poisoning Affects Pets
While humans are at risk, pets—especially dogs—are also susceptible to mushroom toxicity. Dogs are naturally curious and may eat mushrooms while exploring yards, parks, or hiking trails.
The most common symptoms of mushroom poisoning in pets include:
Vomiting and diarrhea
Lethargy and weakness
Tremors or seizures
Difficulty breathing
Organ failure (in severe cases)
Some of the deadliest mushrooms for dogs include Amanita species and Galerina species. If you suspect your pet has ingested a wild mushroom, contact a veterinarian or the ASPCA Animal Poison Control Center immediately.
Types of Mushroom Poisoning
The severity of mushroom poisoning depends on the species consumed, the amount ingested, and the individual’s health condition. Poisonous mushrooms affect the body in four primary ways:
Gastrointestinal Irritants: Many toxic mushrooms, such as Chlorophyllum Molybdites cause nausea, vomiting, and diarrhea within hours of ingestion.
Neurotoxic Mushrooms: Some mushrooms, such as Inocybe species, affect the nervous system, causing hallucinations, confusion, and seizures.
Hepatotoxic Mushrooms: Mushrooms like Amanita phalloides destroy liver cells, often leading to fatal liver failure if untreated.
Nephrotoxic Mushrooms: Some species, like Cortinarius spp., cause kidney failure, leading to long-term organ damage.
What to Do If Mushroom Poisoning Is Suspected
If you or someone you know consumes a wild mushroom and experiences adverse symptoms, take the following steps:
Call Poison Control Immediately: 800-222-1222 The Oklahoma Poison Control Center can provide guidance on treatment options.
Collect a Sample: If possible, safely store a sample of the mushroom for identification.
Seek Emergency Medical Care: If symptoms are severe, go to the nearest hospital.
How to Stay Safe While Foraging
Foraging can be a rewarding experience, but safety should always be a priority. Here are five essential tips to avoid mushroom poisoning:
Never Eat a Mushroom Unless You Are 100% Certain of Its Identity. Many toxic mushrooms closely resemble edible species.
Use Multiple Identification Resources. Books and mushroom identification guides can help you cross-reference species.
Join a Local Mycology Group. Oklahoma has several foraging communities that can provide guidance and education. Oklahoma Fungi offers free guided mushroom identification tours to help beginners learn safely.
When in Doubt, Throw It Out. If you’re uncertain about a mushroom’s identity, do not eat it.
Keep Pets Away from Wild Mushrooms. Regularly inspect your yard for mushrooms that may have sprouted overnight.
Mushroom foraging is an exciting and rewarding activity, but it comes with risks. By educating yourself on common toxic species and their symptoms, you can prevent accidental poisonings for yourself, your family, and your pets. If you suspect mushroom poisoning, contact the Oklahoma Poison Control Center immediately. Stay informed, stay cautious, and forage safely!
