World's deadliest mushroom prompts warning to B.C. mushroom lovers 

Experts advise pickers to attend mushroom festivals, such as Whistler's this weekend, to learn how to harvest safely

  • Photo by Paul Kroeger

The BC Centre for Disease Control and the Vancouver Mycological Society is advising mushroom lovers to be on the look out for the deadly death cap mushroom.

The organizations have issued a joint alert as rainy fall weather sets in and foraging for mushrooms begins. Death cap mushrooms are the deadliest on the planet and have been identified in 100 locations in the Vancouver area.

None have ever been found in Whistler.

BC Drug and Poison Control Centre pharmacist Raymond Li said the centre handled 30 mushroom exposure calls between June and August, but saw 16 in September alone as wet weather helped all types of mushrooms, including death caps, to flourish.

No one knows exactly where or in how many places death cap mushrooms are growing. The Centre for Disease Control (BCCDC) is asking people to report death cap mushrooms or suspected death cap mushrooms to their local mycological club or online through the B.C. government's Invasive Species Working Group report form or mobile app.

The proliferation has prompted the creation of a poster and brochure about the death cap, in part because it is easily mistaken for other edible mushrooms and also because it is found almost exclusively in urban areas of the south coast.

The death cap is not native to B.C., but was brought in on the roots of trees such as hornbeam, European beech, English and red oak, hazelnut, linden and sweet chestnut, which now line streets in Vancouver, the Fraser Valley and parts of the island.

Paul Kroeger, past president of the Vancouver Mycological Society, said death caps weren't identified until long after they became established.

"There was no way of knowing (they were) there when we brought the trees here," he said in the release.

"It was not until the trees matured, about 50 years later, that the mushrooms began to appear."

Death caps are blamed for the death of a Vancouver Island toddler, who ate one in 2016.

Full-grown death caps are often mistaken for paddy straw mushrooms, while immature death caps can look like edible puff balls, but the fairly limited range of the mushroom makes the species easier to avoid, said experts.

"I generally caution against foraging in urban environments because of the added risk," said Kroeger, who will be at Whistler's Fungus Among Us Festival Oct 12 and 13. "If you're foraging, go to a natural forest and go with an expert. There are lots of mushroom clubs, events, and festivals."

On Saturday, Oct. 13, some of B.C.'s most knowledgeable mushroom gurus will lead forays to sites throughout the Whistler valley, some by car and others by foot to investigate mushrooms as part of the annual festival to educate on and celebrate mushrooms. (Tickets at

There are poisonous mushrooms in the natural forest too, including a pine mushroom look-alike in the same family as the death cap known as Amanita smithiana, said Kroeger.

"Many mushrooms are neither harmful nor good to eat but are very important for the health of our forest," he said. "Most mushrooms do more good than harm."

Death cap toxins damage the liver and kidney with symptoms such as cramping, abdominal pain, vomiting, diarrhea and dehydration usually occurring within six to 12 hours after consumption, the BCCDC said in the release.

Those symptoms can fade before returning more severely within 72 hours, leading to severe illness and organ failure that requires medical treatment and, possibly, organ transplants to prevent death.

If you suspect mushroom poisoning, call poison control immediately at 1-800-567-8911.

What to do if you find death cap mushrooms growing:

•Note the location, take careful photographs, and make a report.

•Remove the mushrooms and dispose of them.

•Touching death caps is not a risk but gloves are recommended.

•Do not dispose of death cap mushrooms in your home compost.

•Dispose of them in the municipal compost (green bins) or bag them and put them in the garbage.

•Wash your hands after removing the mushrooms.

With files from Pique Newsmagazine


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