The recent deluge of rain from the atmospheric river has brought much-needed relief to the California water system, doing a lot to refill reservoirs. However, the rain has also raised concern over the rapid growth of amanita phalloides, also known as the death cap mushroom. The death cap accounts for nearly 50 percent of all deaths caused by mushrooms.
In a wonderful new animated video series called Life Up Close by The Atlantic and the HHMI Department of Science Education, the health dangers of the death cap mushroom are described in frightening detail. The mushrooms have been a big problem in rainy years in California. In 2017, there were 14 cases of death-cap mushroom poisonings documented in Northern California. The deadly mushrooms grow in moist earth, and while they may look delicious, they should be avoided. It is estimated that just half a mushroom contains enough poison to kill a human adult. The mushroom’s toxin attacks the liver, and those who are affected develop severe abdominal pain, diarrhea and vomiting. Death can come as quickly as a few days.
Interestingly, death caps are not native to the United States, but likely came from Europe, attached to the roots of other plants, but they have become increasingly prevalent in California, finding a particularly hospitable home around oak trees.
So, if you like to pick and eat wild mushrooms, how do you know what to avoid? Unfortunately, the greenish-beige death cap closely resembles several edible species. We looked around and found several places that warn foragers from eating anything with gills, which harbor the toxin. The Bay Area Mycological Society also has an excellent write up on what to look out for and how to avoid them. You also might check out PBS’s excellent Deep Look video on the subject.