A wet winter in California has produced a surge of wild fungi – a shroom boom that would typically have foragers cheering. But among the chanterelles and porcinis, a much more dangerous fungus called the death cap – also known as the Amanita phalloides – is causing alarm.
The state health department reports that, between late November 2025 and early February 2026, there have been four deaths and 40 hospitalizations linked to consumption of dangerous mushrooms, an outbreak the department describes as “unprecedented”. That’s far above the average for the state, which typically sees fewer than five mushroom-poisoning cases annually.
The people who have been sickened include a seasonal farm worker couple from Oaxaca, Mexico, and have ranged in age from 19 months to 67 years old, according to the Associated Press. Several people have required liver transplants.
Rudy Diaz, the resident mycologist of the Los Angeles Mycological Society, said the illnesses have put the public on edge. When he was out with a friend last month looking at some mushrooms on the side of the trail, a stranger chided him for doing something “risky,” telling him that he should know people had been recently poisoned by mushrooms.
While beginner mushroom pickers may struggle to identify species, among fungi enthusiasts in the know, there is no sense of panic, Diaz says. In southern California, finding mushrooms requires keen eyesight and some understanding of the terrain, so people who are foraging tend to be more trained – which is why he thinks there are fewer cases of poisonings. “The people that are finding mushrooms at all already have some knowledge about the local ecology,” he said.
Death cap mushrooms in France. Photograph: Hemis/Alamy
Still, it’s important for the general public to take heed. People should always be extra cautious when picking mushrooms that they intend to consume, says Jess Starwood, an herbalist, forager and educator who teaches about wild plants in southern California and Arizona. “As more people become familiar with mushrooms through the media and popular culture, fungi are no longer feared,” she says – something that brings challenges and benefits.
The mushrooms look like other varieties of common mushrooms such as puffballs. They typically grow up to 6in across and 6in tall and have a greenish-gray cap and white gills. “Death cap mushrooms can closely resemble edible species in the same family, and novice foragers can very easily make a mistake,” Starwood adds. “In the past, these deadly mushrooms were not as common as they are now, which increases the risk of misidentifying them.”
Eating half a cap or less could be enough to kill a person, with the mortality rates after ingestion reaching as high as 50%. Dog owners should also be aware of the mushrooms, she adds, as they are also deadly to dogs.
The epicenter of the first 35 incidents was the central coast California town of Salinas, which has a large population from central Mexico, where there is a strong culture of mushroom foraging. Diaz guesses people likely mistook the death cap for one of the edible Amanita species they are familiar with in their home country. While many of the residents there speak Spanish, the outbreak has also affected people who speak English, Mandarin, Mixteco, Russian and Ukrainian. As a result, the state’s department of public health has released a new flyer with QR codes sharing the poisonous mushroom advisory in nine languages.
Climate change is also making it more likely that lesser-known species of mushrooms will pop up in places where they are rarely seen. Wet winters mean a lot more mushrooms, and often nontypical species show up in areas they haven’t appeared in before, Starwood says. This could mean death caps show up in new areas where other edible mushrooms have been collected for years. The western destroying angel mushroom (Amanita ocreata) is also highly toxic and common in coastal regions of California through April.
The season for the death cap is now over in southern California but continues in northern California. The experts advise inexperienced mushroom hunters to seek out a local mycological society or foraging group to learn first-hand from experienced local experts about how to safely eat wild mushrooms.
“It took me several years of becoming familiar with the edible Amanita species of California before I had the confidence to eat them,” said Diaz.
The state health agency also advises people to only purchase mushrooms from trusted grocery stores. Death cap mushrooms are still poisonous even after cooking, boiling, freezing or drying. They also say to seek help immediately if someone has a suspected poisoning. Symptoms can include stomach pain, cramping, fatigue, nausea and diarrhea. More serious damage to the liver happens within a few days.
Starwood adds that relying on an app can be dangerous as they are known to make mistakes. “Going with an experienced guide who can teach hands-on in the field is the best resource,” she says. “If you’re uncertain, don’t eat it.”
