Death Cap Mushroom Warning Issued By Park District

EAST BAY — The weather is supposed to be gorgeous this holiday weekend which will doubtless draw many people outside and into our East Bay Regional Parks. But the park district has issued a warning about gathering mushrooms — two of the world’s most toxic mushrooms grow wild in the parks.

The death cap (Amanita phalloides) and the Western destroying angel (Amanita ocreata) contain amatoxins, molecules that are deadly to people, dogs, and other animals.

Symptoms may appear up to 12 hours after eating them and include severe gastrointestinal distress, liver and kidney failure, and, if treatment is not sought immediately, death.

“Both of these mushrooms can be lethal to humans and pets if consumed” Park District Naturalist Trent Pearce warns. “They are mainly associated with oak trees and can be found growing anywhere oak roots are present.”

Although the death cap is mainly associated with oak trees, it has been found growing with other hardwoods. The death cap is not native to California but was accidentally introduced to North America on the roots of European cork oaks.

The Western destroying angel is associated exclusively with oaks. It is native to California.

“Collecting any mushrooms in East Bay Regional Parks is not allowed,” said park district spokesman Dave Mason. “Dog owners should keep a close watch on their dogs during the winter months. Pet owners should contact a veterinarian immediately if they suspect their pet may have eaten a toxic mushroom.”

According to the park district, death cap and Western destroying angel mushrooms are responsible for most cases of mushroom poisonings in California, but Galerina and Lepiota mushroom species, which also occur in the Bay Area, are also toxic.

Photos of all of the toxic mushrooms are available online.