Are backyard mushrooms poisonous?

Mushrooms that grow in backyards can potentially be poisonous. Many types of poisonous mushrooms can grow in yards, gardens, and parks. While some poisonous mushrooms cause mild stomach upset, others can cause severe illness and even death if eaten. It’s important to learn how to identify backyard mushrooms and take precautions.

Quick Answers

Here are quick answers to common questions about poisonous backyard mushrooms:

Are most backyard mushrooms poisonous?

No, most backyard mushrooms are not poisonous. However, it’s difficult for the average person to distinguish between poisonous and non-poisonous varieties. It’s best to avoid eating backyard mushrooms unless you are an expert at mushroom identification.

What are some common poisonous backyard mushrooms?

Some common poisonous mushrooms found in yards and gardens include the death cap mushroom, destroying angels, and the autumns skullcap. Even mushrooms that are typically edible can be poisonous if they absorb toxins from the environment.

How can you tell if a backyard mushroom is poisonous?

There is no one single way to tell if a mushroom is poisonous just by looking. Poisonous mushrooms can look very similar to non-poisonous ones. Specialized knowledge of mushroom species as well as spore prints, chemical testing, or DNA analysis are required for positive identification.

What should you do if you eat a poisonous mushroom?

If you suspect you have eaten a poisonous mushroom, call poison control or 911 immediately. Try to save samples of the mushroom for identification. Seek emergency medical attention as soon as possible; outcomes are better the earlier treatment begins.

Identifying Backyard Mushrooms

There are thousands of mushroom species found in backyards around the world. Most are harmless, but some contain toxins that can cause serious harm. Poisonings happen when toxic backyard mushrooms are accidentally consumed.

Positive identification of any backyard mushroom is a must before considering eating it. This requires specialized knowledge, experience with mushroom species, access to field guides, and often microscopy or chemical testing.

When trying to identify a mushroom, important features to look for include:

  • Cap shape, size, color, texture
  • Gills or pores on the underside of cap
  • Stalk shape, size, color, presence of ring or volva
  • Color of spore print
  • Habitat—where it was growing
  • Scent
  • Bruising reactions

Use a reputable field guide that provides detailed descriptions, scientific names, and multiple photos of mushrooms that grow in your region. Apps can help with identification but should not be solely relied upon.

Common Poisonous Backyard Mushrooms

Some of the most toxic mushroom species that may pop up in backyards include:

Death Cap Mushroom (Amanita phalloides)

The death cap mushroom is one of the most deadly mushrooms worldwide. They can grow under trees in yards and parks. Just one mushroom contains enough toxin to kill an adult human. Death caps cause kidney and liver failure.

Destroying Angels (Amanita species)

Closely related to the death cap, destroying angels mushrooms also contain lethal amatoxins. They grow in forests and sometimes spread to wooded edges of yards and gardens. Destroying angels cause severe gastrointestinal distress, kidney and liver damage, and can be fatal.

Autumn Skullcap (Galerina marginata)

These small brown mushrooms grow on wood chips, mulch, or other decaying organic matter. They contain the same toxins as destroying angels. Just a few mushrooms can be enough to kill.

Podostroma cornu-damae (Deadly Webcap)

This toxic mushroom is found widely across North America and Europe in yards, gardens, and green spaces. It causes severe gastrointestinal illness and can be deadly in large amounts.

Jack O’Lantern Mushrooms (Omphalotus species)

Jack O’Lanterns glow in the dark and are sometimes found growing on buried wood or tree stumps in yards and gardens. While not deadly, they contain toxins that cause severe cramps, vomiting, and diarrhea.

Fly Agaric (Amanita muscaria)

With their bright red caps and white spots, fly agarics are likely the most recognizable backyard mushroom. They contain neurotoxins and hallucinogens that can cause delirium, sweating, twitching, and psychosis.

Poisonous Mushroom Lookalikes

Many poisonous mushrooms closely resemble edible species. Some common deadly lookalikes to watch out for include:

Poisonous Mushroom Lookalike Mushroom
Death caps Paddy straw mushrooms
Destroying angels Button mushrooms, common in grocery stores
Jack O’Lanterns Chanterelles
Podostroma cornu-damae Black trumpet mushrooms
Autumn skullcaps Common brown mushrooms

It takes an expert eye to reliably distinguish edible mushrooms from toxic lookalikes. For beginners, it’s safest to avoid eating any backyard mushrooms unless they are commercially grown varieties.

Toxic Tricholoma Mushrooms

Mushrooms in the Tricholoma genus contain toxins that can cause severe gastrointestinal illness. T. pardinum, T. tigrinum, T. pessundatum, and other Tricholoma species may grow in yards and should be avoided.

Tricholoma pardinum (Tigertop)

This mushroom has a fuzzy, scaly brown cap and white gills. It causes stomach cramps and vomiting if eaten raw or undercooked.

Tricholoma tigrinum (Tiger Tricholoma)

Named after its bright red-and-yellow striped cap, this mushroom leads to delayed liver toxicity several days after being eaten.

Tricholoma pessundatum (Unsafe Tricholoma)

This plain brown mushroom causes severe GI distress. It can be mistaken for other harmless brown mushrooms.

Other toxic Tricholoma mushrooms share similar effects to the species above. Consuming multiple mushrooms intensifies toxicity.

Gastrointestinal Irritants

Some mushrooms contain chemicals that cause gastrointestinal upset. While not deadly, eating them leads to cramping, vomiting, and diarrhea.

Chlorophyllum molybdites (The Vomiter)

One of the most commonly consumed poisonous mushrooms in North America. This large, green-capped mushroom can grow in grassy areas. Always cook well before eating.

Entoloma species (Pinkgills)

These small mushrooms have pinkish spore deposits on the gills. They sometimes grow in lawns and cause cramps if eaten raw.

Boletus species (Boletes)

Some boletes contain toxins, especially when raw. Only eat after thorough cooking. Avoid red-pored boletes.

Consuming these mushrooms may not be deadly, but can still have severe effects. Always cook backyard mushrooms thoroughly before eating.

Toxins in Backyard Mushrooms

Various classes of toxins are responsible for mushroom poisonings, with effects ranging from mild to deadly:

Amatoxins

Extremely toxic compounds found in death caps and destroying angels. Amatoxins inhibit RNA synthesis leading to liver and kidney failure.

Orellanine

Causes kidney failure 1-3 weeks after ingestion. Found in certain Cortinarius mushrooms that may grow under trees.

Muscarine

Causes increased sweating, salivation, and tears. Found in fly agarics and other white-spotted red mushrooms.

Ibotenic acid

Neurotoxin and hallucinogen in Amanita muscaria mushrooms. Causes delirium, twitching, andloss of coordination when ingested.

Gyromitrin

Converts to toxic monomethylhydrazine in the body. Causes nausea, vomiting, seizures, and liver damage.

Coprine

Causes an uncomfortable alcohol-like reaction when consumed with alcohol. Found in inky caps.

Multiple unknown gastrointestinal irritants are also found in some backyard mushrooms.

Signs of Mushroom Poisoning

If you have consumed backyard mushrooms, watch for the following symptoms of poisoning:

  • Nausea, vomiting, diarrhea – Can start in as little as 30 minutes
  • Abdominal pain and cramping
  • Excessive sweating or salivation
  • Vision changes, shaking, confusion, delirium
  • Jaundice (yellowing skin and eyes)
  • Kidney failure or liver failure

Severity depends on the amount eaten and individual sensitivity. The absence of early symptoms does not rule out poisoning. Some toxins cause delayed effects.

First Aid for Mushroom Poisoning

If you suspect you are suffering from mushroom poisoning, immediately seek medical help. The sooner treatment begins, the better the outcome. Take these actions right away:

  1. Call 911, poison control, or go to an emergency room.
  2. Save samples of the mushrooms for identification. Store in paper bags in the refrigerator.
  3. Note when symptoms began and what they are.
  4. Do not induce vomiting unless instructed by poison control.
  5. Rinse mouth and drink plenty of water if able.

Some types of mushroom poisoning have no treatment other than supportive care. However, if the mushroom species can be identified, medications and antidotes are available for some toxins.

Preventing Backyard Mushroom Poisoning

To avoid mushroom poisoning:

  • Never eat any backyard mushrooms unless you are a mushroom expert and 100% certain of the identification.
  • Teach children never to touch or eat wild mushrooms.
  • Remove suspected toxic mushrooms growing in your yard.
  • Keep pets away from unknown mushrooms.
  • Have an expert identify mushrooms growing on your property.

When foraging for wild edible mushrooms, only collect from known safe locations. Always cross-reference mushroom field guides and consult experts for identification.

Edible Backyard Mushrooms

Very few wild mushroom species are recommended for beginner foragers. Stick to these well-known edible mushrooms if considering eating backyard fungi:

Morels (Morchella species)

Morels have a honeycomb-like cap and hollow stem. They have few poisonous lookalikes.

Chanterelles (Cantharellus cibarius)

Funnel-shaped golden chanterelles have gills that run down the stem. They have a fruity aroma.

Chicken of the Woods (Laetiporus sulphureus)

These shelf mushrooms have bright orange caps in rosette shapes. They grow on tree trunks.

Puffballs (Lycoperdon species)

Puffballs form round white masses before releasing a cloud of brownish spores when touched.

Always confirm identity before eating any mushroom. Only harvest edible mushrooms from uncontaminated areas.

Conclusion

Many toxic mushrooms naturally occur in backyards and gardens. While some have mild effects, others contain lethal toxins. Positive identification is necessary before consuming any backyard mushrooms. Prevention through proper identification and control of mushroom growth is key to avoiding poisonings. If you suspect you ate a poisonous mushroom, seek immediate emergency medical care for the best chances of recovery.

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