Natural History Wanderings

Due to this year’s early rainy season, wild mushrooms are popping up in great numbers throughout East Bay Regional Parks. Mushrooms are an ecologically important part of the parklands and can look beautiful—but some of them contain dangerous toxins. The death cap (Amanita phalloides) and western destroying angel (Amanita ocreata) are two of the world’s most toxic mushrooms, and both can be found in Regional Parks during the rainy season. 

The death cap and western destroying angel mushrooms contain amatoxins, molecules that are deadly to many animals. Symptoms may not appear until up to 12 hours after consumption, beginning as severe gastrointestinal distress and progressing to liver and kidney failure if treatment is not sought immediately. 

Both of these mushrooms can be lethal to humans and pets if consumed. Pet owners should contact a veterinarian immediately if they suspect their pet may have eaten a toxic mushroom. They are mainly associated with oak trees and can be found growing anywhere oak roots are present. Collecting any mushrooms in East Bay Regional Parks is not allowed.

Read more Annual Wild Mushroom Advisory in East Bay Regional Parks | East Bay Parks