If you’re interested in foraging for wild mushrooms, it’s essential to know how to identify the good from the bad. Mushrooms are nutritious because of their high fiber and B-vitamin content. These delicious fungi make great snacks and side dishes. Most edible mushrooms look different from poisonous varieties. However, there are a few doppelgangers, so it’s really important to keep your eyes peeled.
Over millions of years, mushrooms developed poisonous compounds within their tissues in an effort to avoid being eaten by animals. Mammals with a strong sense of smell are put off by the aroma of poisonous mushrooms. Birds, which use visual cues to evaluate prey, avoid brightly colored mushrooms.
Despite their small size, chemicals in mushrooms can pose a health risk to people. There are three types of mushrooms: poisonous (lethal), edible, and hallucinogenic. Edible mushrooms are inert; they have no compounds that injure the body. Hallucinogenic and poisonous mushrooms can cause hallucinations and even death.
This article takes a look at 9 species of poisonous mushrooms in the United States. We’ll discuss how you can identify them, where they grow, and what if any, edible mushrooms they are often confused with.
How to Identify Poisonous Mushrooms
Some types of poisonous mushrooms have physical traits that will clue you into their lethality. These traits include a certain shape, color, growth pattern, or texture.
Wherever you go mushroom hunting, make sure you bring along a glossary or guide with mushroom types in the area. This will help you identify the edible mushrooms along with toxic ones that look similar.
There are over 250 types of poisonous mushrooms in the United States, but this guide will help you recognize the most common toxic species.
9 Common Poisonous Wild Mushrooms
If you come across a poisonous mushroom while foraging, it’s best to leave it alone. Some poisonous mushrooms have compounds that can rub off your hands and cause toxicity! It may be wise to take a photo of the mushroom for reference. That way, you’ll have a better understanding of what to avoid when foraging in the future.
1. Death Cap
- Scientific name: Amanita phalloides
- Average size: 2.25” to 6” in diameter.
- Color: Pale yellowish-white.
- Can be found: In temperate regions like northern California and the Northeast United States
The death cap mushroom is the most lethal mushroom in the United States and even the world. They weren’t originally native to the United States and were probably introduced during the 1800s when pioneers immigrated from Europe.
Unfortunately, their bland appearance often leads to them being mistaken for edible mushrooms, especially a mushroom from Southeast Asia called the Paddy-Straw mushroom. Most fatalities and injuries from consuming death caps are by people who weren’t familiar with the existence of the mushroom; they thought it was a Paddy-Straw mushroom.
Poisoning from a death cap requires immediate medical attention from a hospital. Sometimes the only cure is a liver transplant.
It’s the most poisonous mushroom in the world. If you are foraging for mushrooms and wonder if the mushroom you’ve collected is a death cap, do not eat it. It’s better to play it safe.
2. Funeral Bell
- Scientific name: Galerina marginata
- Average size: .4” to 2.75” in diameter
- Color: Light brown to yellow with white underside
- Can be found: Pacific Northwest & northern forests
The funeral bell is also known as the deadly skullcap. This mushroom grows throughout North America and most of the Northern Hemisphere.
Groups of them concentrate around dead trees, stumps, and the base of fallen logs. Where there’s one, there are usually many more.
Identify a funeral bell by way of its brownish-tan cap. It’s bell-shaped and slender. The underside has many thin gills all emanating outward from the center.
3. Eastern Jack O’Lantern
- Scientific name: Omphalotus illudens
- Average size: 2” to 4” in diameter.
- Color: Orange
- Can be found: In Eastern North American forests
The eastern jack O’Lantern mushroom has a curious growth pattern that will help you recognize it in the wild. The gills of this mushroom occasionally glow in the dark.
The glowing phenomenon can happen for up to two days after the mushroom is picked. It usually grows out of the stumps of trees or near mature trees’ root systems.
This mushroom is also pumpkin-colored, one reason behind its name. They also grow in clumps together, while chanterelles grow alone. This mushroom is completely orange, from cap to underside.
4. Destroying Angel
- Scientific name: Amanita bisporigera
- Average size: 4” in diameter
- Color: White
- Can be found: In the Eastern United States
The Destroying angel mushrooms are a type of toxic fungus that grows in the eastern United States. It’s one of three related species of mushrooms from the genus Amanita that are all toxic.
Recognize it by way of its tall, thick stalk, called a stipe. The bell of this mushroom is usually wide and flat. They prefer to grow near trees because they establish give-and-take relationships with the fungus living in trees’ roots.
5. Pholiotina rugosa
- Scientific name: Pholiotina rugosa
- Average size: 1” in diameter
- Color: Dusky Brown
- Can be found: in the Pacific Northwest
Unlike the other mushrooms on this list, the P. rugosa mushroom doesn’t have an informal name. It’s still poisonous, however, and you’d best avoid it! P. rugosa lives in the United States, but is especially common in the Pacific Northwest. There, it takes advantage of the forests and moist conditions to thrive.
P. rugosa is a small, slender mushroom. It has a small brown cap just over an inch in diameter and a skinny stripe. The stipe occasionally has a ring around it that measures halfway up the stipe.
6. Fool’s Funnel
- Scientific name: Clitocybe rivulosa
- Average size: 2” in diameter
- Color: White
- Can be found: in fields and open meadows of the United States
The Fool’s funnel is a toxic mushroom native to the United States. They can be difficult to identify because their color changes depending on how much water is in their environment. Damp fool’s funnels are ‘frosted’ with brown pigment. When it’s dry, they are white entirely.
Fool’s funnel is one of the more commonly ingested toxic mushrooms because it grows in open fields and looks similar to the ivory funnel. They often grow in groups that are called fairy rings.
7. False Morels
- Scientific name: Gyromitra esculenta
- Average size: 2.25” to 6” in diameter.
- Color: Dark reddish brown
- Can be found: In the Western United States
The false morel is so named because it looks similar to the edible morel mushroom. These mushrooms are dark in color. They appear similar to coral with their striations and ridges that look like crumpled paper.
False morels cause stomach and digestive issues when eaten. They aren’t as deadly as the death cap, but they can still cause toxicity and death.
Both morels and false morels grow near trees, but there are several ways to tell them apart. False morels have crumpled caps instead of a honeycomb pattern. While symmetrical, they are not hollow inside like real morels are.
8. Fly Agaric Mushroom
- Scientific name: Amanita muscaria
- Average size: 3” to 8” in diameter.
- Color: Usually red, but can be yellow or orange
- Can be found: Across the United States
When you think of a toxic mushroom, chances are you imagine the silhouette of the fly agaric mushroom. Its bright red cap is a signal to potential predators that it is poisonous. Do not touch!
Fly agaric mushrooms have a white stripe and white warts on the cap. Depending on where you are in the United States, there are different varieties with differently colored caps. The western United States is home to a peachy-colored fly agaric and the eastern United States grows yellow fly agarics.
9. Deadly Galerina
- Scientific name: Galerina autumnalis
- Average size: .5” to 1.5” in diameter.
- Color: Reddish-brown
- Can be found: Across the United States
The deadly galerina mushroom has a similar toxic load as the death cap and the destroying angel. This mushroom contains a substance called ‘amanitin,’ which has a delayed onset of symptoms, so it’s often difficult to determine what caused the toxification.
Deadly galerinas’ caps can be flat or curled inward. The stipe is irregular and can be thick or very thin. They grow in groups especially around fallen coniferous trees.
Anna is a wildlife biologist who graduated from Texas A&M in 2020. She enjoys studying and learning about wild birds and wildlife of all types.