Deadly mushrooms may not be brightly colored or stand out in any way. Most of them look quite like any other edible or benign mushroom. Adequate treatments for some mushroom poisonings don't exist, so one mistake can be deadly even if you seek treatment. It takes a great deal of training to identify subtle differences in mushroom species, and it does not pay to take chances. It is better to buy the mushrooms you eat in a store and enjoy looking at the wild ones while leaving them alone. These mushrooms are also dangerous to pets and other animals.
Gyromitra esculenta - “False Morels”
False morels are potentially deadly if eaten raw. People in Scandinavia, Eastern Europe and the upper Great Lakes region of North America eat them as a delicacy. They affect the liver, central nervous system and kidneys. A few hours after eating false morels, they cause vomiting and diarrhea. Symptoms then progress to dizziness, lethargy and a headache. Over the course of five to seven days can come delirium, coma and even death. They are especially dangerous to young children and pregnant women. False morels have the appearance of brain matter.
Amanita ocreata - “Western North American Destroying Angel”
This mushroom grows in the Pacific Northwest of North America and parts of California. It often grows near oak trees. It is white with brown splotches. As little as 1/2 cup of these mushrooms can be fatal. About 40 percent of all cases of ingestion are fatal. Treatment sometimes helps sustain life after ingesting Destroying Angels, but it is not a cure and does not always work. The mushrooms cause gastrointestinal pain, vomiting and diarrhea. Symptoms only last two to three days, but internal organ damage is permanent. Signs of permanent organ damage are jaundice, delirium, diarrhea, seizures and coma. Death from liver failure usually occurs within six to 16 days.
Amanita smithiana - (No Common Name)
This mushroom is also white with brown splotches. It grows in the Pacific Northwest and northern coastal California. It causes kidney failure very quickly. In two to 12 hours this mushroom causes nausea and vomiting. Death from kidney failure occurs within two to six days. It is especially hard to distinguish this mushroom from its benign cousins after a rain when it is wet.
Amanita phalloides - “Death Cap”
Death cap grows all over Europe and is the most commonly ingested poisonous mushroom because it looks so much like edible varieties. It damages the liver and kidneys and there is no antidote. It is an uneven gold color. It is native to Europe and rare in North America, but is common in the San Francisco Bay area of California. These mushrooms are also common in Asia. Only 2 to 3 g can be deadly. Within five to 12 hours they cause abdominal pain, nausea, diarrhea and vomiting. Symptoms seem to go away in two to three days, but a coma and death from kidney or liver failure is common.
Amanita bisporigera - “Destroying Angel”
This mushroom causes diarrhea, vomiting, cramps, delirium and convulsions within five to 12 hours. As little as half of the mushroom can be fatal. Fast treatment is critical for survival. The mushroom is white and smooth. It is most common in North America.
Amanita virus - “European Destroying Angel”
These European mushrooms, like many deadly mushrooms, look much like some edible varieties. They actually taste good. Symptoms begin from six to 24 hours after ingestion. They include abdominal pain, vomiting and diarrhea. Symptoms last from six to nine hours and disappear for about 24 hours. Within seven days death usually occurs from severe liver damage. Gastrointestinal bleeding and coma due to kidney failure precede death. It is a very average looking white mushroom.
Amanita verna - “Fool’s Mushroom”
Fool’s mushroom is a beautiful, white variety that grows in Europe. The symptoms and appearance of fool’s mushroom are almost identical to those of the Death Cap.
Cortinaruis rubellus - “Deadly Webcap”
The Deadly Webcap grows in Europe. It is gold colored and looks like many benign species. It is lethal in doses of 100 to 150 g. Many people eat it because they think it is a hallucinogenic mushroom. Symptoms appear two days to three weeks after ingestion. The symptoms are nausea, vomiting, stomach pains and headache. Then the symptoms of kidney failure begin, including extreme thirst, frequent urination and kidney pain. There is no antidote, but early treatment can usually prevent death.
Cortinarius orellanus - “Fool’s Webcap”
Fool’s Webcap looks like Deadly Webcap, and is also common in Europe. The symptoms are virtually identical.
Chitocybe dealbata - “Ivory Funnel”
The Ivory Funnel is also called the Sweating Mushroom because of the symptoms of poisoning. It causes profuse sweating, salivation and tears within 15 to 30 minutes of ingestion. Abdominal pain, nausea, diarrhea, vomiting, blurred vision and labored breathing follow. There is an antidote, so prompt treatment can prevent permanent injury or death. It is an attractive white mushroom with wavy edges.