They appear like magic, and often in places where they have never been seen before. Their scents vary wildly: Some smell like anise, others like fruit, cucumbers, green corn, creosote, fish, radishes, rotting meat, garlic, or raw potatoes. They range from dull grays and browns to brilliant reds and oranges, sometimes fantastically polka-dotted; their texture may be frilly, shiny, slimy, bumpy, or smooth. You can find them on trees, in the grass, underground. They can cost hundreds of dollars an ounce and are served in the most sophisticated restaurants. People hunt them like treasure. And some of them can kill you. While much of North America remains in a deep-freeze, in some areas February marks the beginning of mushroom season.
Mushrooms are among the most mysterious of life forms. Some kinds are edible -- and delicious. Others cause hallucinations and other psychological and perceptual effects, and have been used in spiritual rituals. Many species are unstudied, their ingestibility unknown. And a number of species contain dangerous toxins, many of which are not yet fully understood.
Every year poison centers and emergency rooms treat people who have been poisoned or made ill by mushrooms. These range from people taking "magic mushrooms" for their hallucinogenic effects to gourmands who have tragically misidentified a species to toddlers who have swallowed mushrooms growing in the backyard. Unfortunately, no simple test can determine whether a mushroom is edible or poisonous. The only way to be certain is to positively identify the species you have found. Only experience can teach you to recognize characteristics that differentiate edible species from poisonous ones, and with some species you cannot be too careful. Some mushroom hunters will even examine a mushroom's spores microscopically to be sure their identification is correct. In short, before you eat any wild mushroom, check every possible feature and clue, consult field guides or scientific literature, and be 100 percent sure of proper identification (consulting experts if necessary). Only those who truly know what they’re doing should even consider eating wild mushrooms. If any doubt remains about the edibility of a species, do not eat it.
Many mushrooms cause mild to severe poisoning, and only a few cause life-threatening illness. Some mushroom toxins affect the central nervous system, others the peripheral nervous system, and most cause mild to severe gastrointestinal upset. Some people react adversely to species that are harmless to most or to species that they have eaten before without ill effects. Below is a list of mushroom toxins, some of the species that contain them, and a description of the symptoms known to occur. (This is not a comprehensive list of all poisonous mushrooms.) If you suspect you have mushroom poisoning, contact a poison control center (call 1-800-222-1222 or visit the American Association of Poison Control Centers website) and seek medical attention immediately. Bring along samples, preferably uncooked, of the mushrooms you have eaten.
Mushrooms: Amanita species including A. phalloides (Death Cap), A. virosa complex (Destroying Angel), A. verna, A. bisporigera, A. ocreata; Galerina species, including G. marginata, G. autumnalis, G. venenata; Lepiota species, including L. josserandii, L. helveola, L. castanea; and Conocybe filaris.
Symptoms of this very dangerous toxin occur 6 to 24 hours (rarely 48 hours) after ingestion, typically in 10 to 14 hours. They include severe abdominal pains, nausea, vomiting, and diarrhea, lasting for one or more days. A short remission takes place, and the victim may believe he or she has recovered. By the third or fourth day, however, pain recurs, along with liver dysfunction, jaundice, renal failure, convulsions, coma, and without adequate treatment, death within five to ten days. With sustained medical assistance, recovery can take place in one to two weeks. Toxic amanitas have caused about 90 percent of all fatal mushroom poisonings, and 50 percent of those who ingest amanitin die. As a rule of thumb, do not eat any Amanita species, and be especially careful in identifying Amanita look-alikes or any other white mushrooms.
Toxin: Monomethylhydrazine (MMH)
Mushrooms: Gyromitra species, including G. esculenta and G. brunnea; and related Helvella, Verpa, and Cudonia species.
Symptoms occur 6 to 12 hours (rarely 2 hours) after ingestion. They include a bloated feeling, nausea, vomiting, watery or bloody diarrhea, abdominal pains, muscle cramps, faintness, loss of coordination, and in severe cases convulsions, coma, and death. With medical attention, recovery can occur within hours. The toxin, also known as gyromitrin, develops a compound similar to one used in the manufacture of rocket fuel. It is advisable to avoid ingesting any false morels.
Mushrooms: Cortinarius species, including C. gentilis and others.
Symptoms occur 3 to 14 days (rarely to 21 days) after ingestion, and ultimately result in acute or chronic renal failure, which can result in death. A kidney transplant is sometimes required, and recovery can take as long as six months. Symptoms may include nausea, vomiting, thirst, frequent urination, and the sensation of being cold, accompanied by shivering. The seriousness of orellanin poisoning makes it advisable to avoid eating any "little brown mushrooms," or LBM's, that resemble Cortinarius species.
Mushrooms: Clitocybe species, including C. dealbata and C. dilatata; most Inocybe species; some Boletus species.
Symptoms occur within a half hour and include profuse perspiration, salivation, tears, blurred vision, tunnel vision, abdominal cramps, watery diarrhea, constriction of the pupils, a fall in blood pressure, and slowing of the pulse. Although symptoms usually subside in 6 to 24 hours, severe cases may require hospitalization, and death has been reported in people with preexisting illness.
Toxins: Ibotenic Acid and Muscimol
Mushrooms: Amanita species, including A. muscaria, A. frostiana, A. pantherina.
Symptoms occur 30 minutes to 2 hours after ingestion. They include dizziness, lack of coordination, delusions, staggering, delirium, raving, profuse sweating, muscular cramps and spasms, hyperactivity, and deep sleep. Recovery usually takes place within 4 to 24 hours; some cases require hospitalization. Other Amanita species are implicated in most fatal mushroom poisonings, and it is wise to avoid this genus altogether. Be sure to positively identify any look-alike species before eating them.
Mushrooms: Coprinus atramentarius, Clitocybe clavipes.
Symptoms are precipitated by the ingestion of alcohol, as a substance in the mushroom inactivates an enzyme that detoxifies alcohol in the system. This effect can occur as long as five days after eating the mushrooms. Symptoms, usually occurring about 30 minutes after the alcohol is taken, include flushing of the face and neck, distension of neck veins, swelling and tingling of hands, a metallic taste in the mouth, palpitations, and a drop in blood pressure. Nausea, vomiting, and sweating may then occur. Recovery is spontaneous and usually occurs within 2 to 4 hours.
Toxins: Psilocybin and Psilocin
Mushrooms: Psilocybe species, including P. baeocystis, P. caerulipes, P. coprophila, P. cubensis, P. cyanescens, P. pelliculosa, P. semilanceata, P. stuntzii; Conocybe smithii; Gymnopilus spectabilis; Panaeolus cyanescens, P. subbalteatus.
These are the toxins that give hallucinogenic mushrooms their effects. The reactions that result from ingesting these mushrooms vary considerably; none should be eaten casually. Symptoms occur within 30 to 60 minutes, rarely as long as 3 hours later. They include mood shifts, which can range from pleasant to apprehensive. Symptoms may often include unmotivated laughter, hilarity, compulsive movements, muscular weakness, drowsiness, visions, then sleep. Recovery usually takes place within six hours. The victim should be assured that the symptoms will pass.
Mushroom: Paxillus involutus
Symptoms occur one to three hours or more after ingestion. They result from a gradually acquired sensitivity to the species, and include destruction of red blood cells, vomiting, diarrhea, cardiovascular irregularity, and possibly kidney failure. They usually disappear in two to four days, but can last much longer in severe cases and may require hospitalization.
Mushroom: Amanita smithiana
Symptoms occur 4 to 11 hours after ingestion, and include abdominal pain and diarrhea, followed by kidney or liver failure. These poisonings are not well studied. They resemble orellanin poisonings, but the onset of symptoms is much quicker.
A large number of mushrooms can cause gastrointestinal illness. Symptoms occur 30 minutes to 3 hours after ingestion. They include mild to serious and severe nausea, vomiting, diarrhea, and abdominal pain. Recovery can take several hours or days, depending on the species, the amount eaten, and the health of the victim. Hospitalization is sometimes required.
Some edible mushrooms are also known to cause occasional adverse reactions, even in people who have eaten them before without any side effects. Symptoms occur within 2 hours. They include nausea, vomiting, and diarrhea. Recovery usually takes place within a few hours.