The East Bay Regional Park District is warning residents to be extra vigilant outdoors because of poisonous mushrooms.
The region is home to two of the world's most deadly mushrooms, the aptly named Death Cap and Western Destroying Angel, according to park officials.
"Both of these species contain amatoxins, a group of molecules that inhibit cellular metabolism in many animals," the district said in a statement. "In mammals, the liver and kidneys are typically the fist organs affected after ingestion."
The toxic mushrooms can be found in any district park with oak trees, including those in and near Pleasanton.
The district is reminding visitors that it's illegal to pick mushrooms or any plants found in the parks.