by Amy Stewart
ELDERBERRY
Sambucus spp.
This fruit, popular in jams, cakes, and pies, is much more dangerous when consumed raw. In 1983 a group of people attending a retreat in central California had to be flown by helicopter to a hospital after drinking fresh elderberry juice. Most parts of the plant, including the uncooked fruit, may contain varying levels of cyanide. Generally, people experience severe nausea and recover.
CASHEW
Anacardium occidentale
There’s a reason why grocery stores don’t sell raw cashew nuts. Cashews are part of the same botanical family as poison ivy, poison oak, and poison sumac. The cashew tree produces the same irritating oil, urushiol. The nut itself is perfectly safe to consume, but if it comes into contact with any part of the shell during harvest, it will give the person who eats it a nasty rash. For that reason, cashews are steamed open, making them partially cooked even if they appear to be raw. In 1982 a Little League team in Pennsylvania sold bags of cashew nuts that were imported from Mozambique. Half of the people who ate them developed rashes on their arms, groin, armpits, or buttocks because some of the bags of nuts contained pieces of cashew shells, which would have had the same effect as mixing poison ivy leaves with the nuts.
RED KIDNEY BEAN
Phaseolus vulgaris
Perfectly safe and healthy, except if eaten raw or undercooked. The harmful compound in kidney beans is called phytohaemagglutinin, and it can bring on severe nausea, vomiting, and diarrhea. People usually recover quickly, but it takes only four or five raw beans to bring on these extreme symptoms. The incomplete cooking of raw beans in a slow cooker is a common source of red kidney bean poisoning.
POTATO
Solanum tuberosum
This member of the dreaded nightshade family contains a poison called solanine, which can bring on burning and gastrointestinal symptoms and even coma and death in rare cases. Cooking a potato will kill most of the solanine in it, but if a potato has been exposed to the light long enough for its skin to turn green, that may be a sign of increased levels of solanine.
ACKEE
Blighia sapida
The ackee fruit plays an essential role in Jamaican cuisine. Only the aril (the flesh surrounding the seeds) is safe to eat, and the fruit must be harvested at a precise point of ripeness or it may be toxic. Ackee poisoning, or Jamaican vomiting sickness, can be fatal if untreated.
CASSAVA
Manihot esculenta
An important food crop in Latin America, Asia, and parts of Africa, the root is cooked in much the same way that potatoes are. A starchy flour derived from the root is used to make tapioca pudding and bread. There’s just one problem: cassava contains a substance called linamarin that converts to cyanide in the body. The cyanide can be eliminated through careful preparation that involves soaking, drying, or baking the root, but this process is imperfect and can take several days. In times of drought, cassava roots may produce higher levels of the toxin, and people in famine-stricken areas may eat more of the root and take less care with preparation.
Cassava poisoning can be deadly. Even at lower levels it can cause a chronic condition known in Africa as konzo. Symptoms include weakness, tremors, a lack of coordination, vision problems, and partial paralysis.
INTOXICATING
Ergot
CLAVICEPS PURPURA
Historians still wonder what caused the bizarre behavior that led eight young girls to be suspected of demonic possession and witchcraft during the winter of 1691 in Salem, Massachusetts. One girl after another went into convulsions, babbled incoherently, and complained of creepy skin sensations. Doctors could find nothing wrong with them, and the best explanation medical science had to offer was that a witch cast a spell over the girls.
FAMILY:
Clavicipitaceae
HABITAT:
Thrives on cereal crops such as rye, wheat, and barley
NATIVE TO:
Europe
COMMON NAMES:
Ergot of rye, St. Anthony’s fire
Almost three hundred years later, a researcher had another idea. Ergot, the toxic fungus that infects rye and contaminates bread, could explain the girls’ bizarre behavior.
Ergot is a parasitic fungus that attaches itself to a flowering cereal grass like rye or wheat. It flourishes in damp conditions and possesses the special trick of being able to mimic the very grain it has infected. It forms a hardened mass called a sclerotium on its host and can nurture dormant spores until the conditions are just right to release them. Millions of ergot spores can be harvested right along with a rye or wheat crop, and the bread produced from those grains can contain enough of the fungus to infect whoever eats it—including some young girls living in Salem during a particularly damp winter.
The alkaloids in ergot constrict blood vessels, causing seizures, nausea, uterine contractions, and eventually gangrene and death. Long before Albert Hofmann extracted lysergic acid from ergot to make LSD, people infected with ergotism had bad LSD-like trips of their own. Hysteria, hallucinations, and a feeling that something is crawling on the skin are all signs of ergot poisoning.
This “dancing mania” was also sometimes called St. Anthony’s fire, a possible reference to the awful burning sensations ergot victims felt, and the eventual gangrenous blisters and peeling skin.
Records going back to the Middle Ages show that from time to time, an entire village would succumb to mysterious illness. Villagers would dance in the streets, go into convulsions, and eventually collapse. This “dancing mania” was also sometimes called St. Anthony’s fire, a possible reference to the awful burning sensations victims felt, and the eventual gangrenous blisters and peeling skin. The disease is believed to have killed over fifty thousand people during that time. Even livestock were not safe: when cows were fed the infected grains, they lost their hooves, tails, and even their ears before they died.
The relationship between these strange behaviors and ergot infestation had only just been discovered in Europe when the Salem witch trials began, but it is unlikely that news of this breakthrough would have reached the colonies. Eventually nineteen people went to the gallows for the crime of casting spells on the girls. They protested their innocence all the way.
If only someone had thought to question the town baker. Judging from weather records, crop reports, the girls’ symptoms, and the fact that the hysteria stopped almost as abruptly as it started, it is entirely possible that the whole event was caused by an outbreak of ergot brought on by an unusually wet winter.
Outbreaks of ergotism are rare today, but a few did occur in the twentieth century. There are still no ergot-resistant strains of ryegrass, but rye farmers now rinse their crop in a salt solution to kill the fungus.
Meet the Relatives There are over fifty ergot species, each favoring a particular kind of grass or cereal crop.
DANGEROUS
FATAL FUNGUS
In 2001, a group of medical researchers reopened an ancient murder case. Claudius, emperor of Rome from 41 to 54 BC, died under mysterious circumstances after several months of bitter fighting with his fourth wife, Agrippina. A modern-day review of his symptoms pointed to poisoning by muscarine, a toxin found in several species of deadly mushrooms. But who fed him this final meal? One expert at the conference suggested that “Claudius died of de una uxore nimia, or one too many wives.”
Another infamous mushroom poisoning case took place in Paris in 1918. Henri Girard was an insurance broker who had some training as a chemist. That turned out to be a good combination for a serial killer: he took out insurance policies on his victims and then killed them using poisons that he obtained from drug wholesalers or mixed in his own laboratory. His poison of choice was a culture of typhoid bacteria, but for his last murder victim, Madame Monin, he prepared a little dish of poisonous mushrooms. She left his house and collapsed on the sidewalk. The authorities eventually caught up with him, but he died before he could go to trial.
Although mushrooms are
not truly plants—they’re fungi—they deserve some mention for the number of deaths they cause. In 1909, the London Globe reported that as many as ten thousand people in Europe died of mushroom poisoning every year. There are few reliable sources today of the number of deaths by mushrooms worldwide, but in the United States, poison control centers get over seven thousand calls a year. In 2005, they reported six deaths from mushroom poisoning. Sporadic outbreaks can kill many more. For example, in 1996, mushrooms killed over a hundred people in Ukraine thanks to an unusually abundant crop in the forest.
Some species contain more toxins than others, but the most dangerous varieties go to work on the liver or kidneys, causing irreversible damage or death.
DEATH CAP
Amanita phalloides
These pale, medium-sized mushrooms found throughout North America and Europe are responsible for an estimated 90 percent of mushroom-related fatalities worldwide. They look similar to the edible paddy straw mushroom popular in Asia, but it takes only about half of a death cap mushroom to kill an adult. The mushroom causes permanent damage to the kidneys and liver, and some victims require liver transplants to survive the ordeal.
A closely related species is the death angel mushroom (Amanita verna or A. virosa), which is regarded as the most poisonous species. Symptoms may not appear for several hours, which could result in delayed treatment with tragic consequences.
CORTINARIUS
Cortinarius spp.
These small, brown mushrooms resemble shiitakes and other edible species but are highly poisonous. The symptoms may be delayed for several days, making it more difficult for doctors to identify and treat. Corti-narius mushrooms can cause seizures, severe pain, and kidney failure.
FALSE MOREL
Gyromitra esculenta
Found throughout North America, this mushroom looks like the delicious, highly sought-after edible morel mushroom. As with most mushroom poisonings, symptoms include nausea, dizziness, and eventual coma, and death is often caused by kidney or liver damage.
FLY MUSHROOM
Amanita muscaria
Reddish orange with white spots, this is one of the most widely recognized mushrooms in the world and is often used in illustrations of fairy tales. The hookah-smoking caterpillar that sat on a mushroom in Alice’s Adventures in Wonderland might have been sitting on mushroom like this one. In fact, the symptoms Alice experienced after she nibbled a bit of the mushroom are not too different from the kind of hallucinations that mark the first signs of poisoning from this species. Dizziness, delirium, and intoxication are sometimes followed by a deep sleep or a coma.
MAGIC MUSHROOM
Psilocybe spp.
Psylocybin and psilocin are hallucinogenic compounds found in different species of mushrooms, but primarily those in the Psilocybe genus. The two compounds are listed as Schedule I controlled substances (defined as having no medical use) by the U.S. Drug Enforcement Administration; however, the agency does not list any particular mushroom species on its schedule.
Psylocybin mushrooms are usually eaten or made into a tea; in addition to hallucinations, the effects may include nausea and vomiting, weakness, and drowsiness. Large doses can bring on panic attacks and psychosis. It grows wild throughout the southern and western United States and ranges from Mexico to Canada. Some species are found in Europe as well. It is easy to confuse psilocybin mushrooms with highly poisonous look-alikes, and people have died from eating the wrong species.
INKY CAP
Coprinus atramentarius
This small white mushroom with a bell-shaped cap is known for its ability to turn as black as ink as it matures. Its poison is particularly devious: victims are only harmed if they eat the mushroom in combination with alcohol. People may experience sweating, nausea, dizziness, and difficulty breathing for a few hours. Most recover, but those who have been poisoned must avoid alcohol for at least a week. Some people experience no harmful effects at all, making this a risky and unpredictable mushroom to experiment with.
PAINFUL
Habanero Chile
CAPSICUM CHINENSE
Imagine: a pepper so hot that popping one in your mouth could send you to the hospital. At first, your eyes will water and your throat will burn; then you’ll start to have trouble swallowing. Your hands and face will go numb. If you’re particularly unlucky, you’ll go into respiratory distress—all over one fiery habanero pepper.
FAMILY:
Solanaceae
HABITAT:
Tropical climates; needs heat and regular water
NATIVE TO:
Central and South America
COMMON NAMES:
Habanero
In the early 1900s chemist Wilbur Scoville developed a test for measuring the heat intensity in chile peppers. A pepper extract is dissolved in water and tasted by a panel of people who do not regularly eat hot peppers and are therefore more sensitive to the taste. The pepper’s Scoville rating is expressed as the ratio of water to pepper extract required to completely quench the fiery flavor. A bell pepper, which contains no heat, would get a rating of 0 SHU, or Scoville heat units. A jalapeño pepper—generally considered to be the hottest pepper any sane person would attempt to chew and swallow—gets a rating of around 5,000 SHU.
If it takes five thousand units of water to dilute the heat in one unit of jalapeño extract, what does it take to render harmless a habanero? Anywhere from one hundred thousand to one million units of water, depending on the cultivar and the growing conditions.
The heat levels approached 1 million Scoville units. As a comparison, the pepper spray used by police officers clocks in at 2 to 5 million units.
Just a handful of peppers vie for the title of world’s hottest, and they are all varieties of Capsicum chinense, commonly called the habanero. The small orange Scotch bonnet variety lends its unique flavor to Jamaican dishes. Another strain, ‘Red Savina’, earned a Guinness World Record in 1994 for the hottest pepper, with a Scoville rating of over 500,000 SHU. But the hottest habanero in the world may come from Dorset, England, an area not known for its spicy cuisine.
An English market gardener developed ‘Dorset Naga’ from the seeds of a Bangladeshi pepper. The best seedlings were selected and grown, and after a few successive generations they had a pepper so hot that it could hardly be used as a flavoring. You could hold the pepper by the stalk and rub it against your food, but to do more than that would be to tempt fate. Two American laboratories tested the peppers using a new technology, high-pressure liquid chromatography. The heat levels approached 1 million SHU. As a comparison, the pepper spray used by police officers clocks in at 2 million to 5 million SHU.
Strangely, the active ingredient in hot peppers, capsaicin, does not actually burn. It stimulates nerve endings to send a signal to the brain that mimics a burning sensation. Capsaicin does not dissolve in water, so grabbing for the water jug to put out the fire in your mouth is useless. However, it will bind to a fat like butter, milk, or cheese. A good stiff drink is also in order, as the alcohol works as a solvent.
But nothing could protect you against the power of Blair’s 16 Million Reserve, a so-called pharmaceutical grade hot sauce made of pure capsaicin extract. A tiny one-milliliter bottle of the clear potion sells for $199 and comes with a warning that it must be used “for experimental/display purposes only” and never as a flavoring for food.
Meet the Relatives? Peppers are another notorious member of the nightshade family, which includes tomatoes, potatoes, and eggplant, along with such evildoers as tobacco, datura, and henbane.
INTOXICATING
Henbane
HYOSCYAMUS NIGER
The particular bit of vegetable wickedness known as henbane was, according to legend, a key ingredient in witches’ flying potions. A salve of henbane, belladonna, mandrake, and a few other deadly plants, applied to the skin, would make anyone feel as if they were flying. Mixtures like this have been called the devil’s own recipe for good reason. In Turkey children play a
game in which they eat various parts of certain plants. A medical study showed that a quarter of the children who played that game became severely intoxicated after eating henbane. Five went into a coma and two died.
FAMILY:
Solanaceae
HABITAT:
Widespread across temperate climates
NATIVE TO:
Mediterranean Europe, North Africa
COMMON NAMES:
Hog’s bean, fetid nightshade, stinking Roger. Henbane means literally “killer of hens.”
Hyoscyamus niger is a weedy annual or biennial that grows to just one or two feet tall and produces yellow flowers, with what have been described as “lurid purple veins.” The small, oval seeds are a dull yellow color and are every bit as poisonous as the rest of the plant.
Although henbane contains alkaloids similar to those found in its close relatives, datura and belladonna, it is particularly known for its rank odor. Pliny the Elder wrote that the various strains of henbane “trouble the braine, and put men beside their right wits; beside that, they breed dizziness of the head.” In fact, staff at the Alnwick Poison Garden in northern England report that two guests have fainted on hot days in the presence of henbane. Was it the heat or the soporific effects of the plant? No one knows for sure, but they warn guests to give this plant a wide berth.