Wicked Plants: The Weed That Killed Lincoln's Mother and Other Botanical Atrocities - Amy Stewart (2009)
Indigenous tribes in South America and Africa have used toxic plants as arrow poisons for centuries. The poisonous sap of a tropical vine, rubbed onto an arrowhead, makes a potent tool for both warriors and hunters. Many arrow poisons, including the tropical vine curare, cause paralysis. The lungs stop working, and eventually the heart stops beating, but there are often no outward signs of agony.
A sturdy, woody vine found throughout South America. It contains a powerful alkaloid called d-tubocurarine that acts as a muscle relaxant. Useful for hunters, it rapidly immobilizes prey, even causing birds to fall from the trees. Any game caught using arrows poisoned with curare would be safe to eat, because the toxin is only effective when it enters the bloodstream directly, as opposed to the digestive tract.
If the animal (or enemy) is not slaughtered right away, death comes within a few hours as paralysis reaches the respiratory system. Experiments on animals poisoned in this manner have shown that once breathing stops, the heart continues to beat for a short time, even though the poor creature appears dead.
The power of this drug was not lost on nineteenth- and twentieth-century physicians, who realized that it could be used to hold a patient still during surgery. Unfortunately, it did nothing to relieve the pain, but it would allow a doctor to go about his work without the distraction of a patient’s thrashing about. As long as artificial respiration was maintained throughout the surgery to keep the lungs functioning, the curare would eventually wear off and leave no long-lasting side effects. In fact, an extract from the plant was used in combination with other anesthesia throughout most of the twentieth century, but new, improved drugs have taken its place.
The word curare has also been used to refer more generally to a wide variety of arrow poisons derived from plants, including:
A South American vine closely related to the strychnine tree, Strychnos nux-vomica. Like curare, it causes paralysis. In fact, the two were often used in combination.
A native African vine containing a cardiac glycoside that goes directly to work on the heart. While a powerful dose may stop the heart, extracts have also been used as a cardiac stimulant to treat heart failure or irregular heartbeats. Nineteenth-century plant explorer Sir John Kirk obtained specimens of the plant to bring back to the Royal Botanic Garden at Kew and inadvertently participated in a medical experiment: he accidentally got a little juice from the plant on his toothbrush and reported a quick drop in his pulse rate after he brushed his teeth.
A member of the mulberry family native to China and other parts of Asia. The bark and leaves produce a highly toxic sap. Charles Darwin’s grandfather Erasmus claimed that the tree’s fumes could kill anyone who went within miles of it. Although this is only legend, references to the noxious fumes of the upas tree can be found in the writings of Charles Dickens, Lord Bryon, and Charlotte Brontë. A character in a Dorothy L. Sayers novel once described a serial killer as “first cousin to an upas tree.” Like other arrow poisons, the sap contains a powerful alkaloid that can stop the heart.
Charles Darwin’s grandfather Erasmus claimed that the upas tree’s fumes could kill anyone who went within miles of it.
POISON ARROW PLANT
An appropriately named shrub native to South Africa that also kills by attacking the heart. Some reports show that it was used in a particularly devious way: the juice was smeared on the sharp seeds of puncture vine (Tribulus terrestris). The seeds grow in the sturdy shape of a caltrop, which is a simple spiked weapon with two or more legs that always lands with one spike pointed up. Metal versions of these weapons have been used since Roman times; it was easy to fling them in the path of an approaching enemy. Puncture vine seeds smeared with the juice of Acokanthera would have been an efficient way to embed the poison in the feet of an attacker, and the half-inch-long spines would slow them down considerably.
William Burroughs drank ayahuasca tea in the jungle and reported his findings to Allen Ginsberg. Alice Walker sought it out, as did Paul Theroux, Paul Simon, and Sting. It has been the subject of a patent dispute, a Supreme Court case, and a number of drug raids.
Tropical forests in South America
Peru, Ecuador, Brazil
Yage, caapi, natem, dapa
The bark of the woody ayahuasca vine, brewed with the leaves of the chacruna shrub, form a potent tea called ayahuasca (or, alternatively, hoasca). Chacruna contains the powerful psychoactive drug DMT (di-methyltryptamine), a Schedule I controlled substance, but the leaves must be activated by another plant, usually Banisteriopsis caapi, before the effects can be felt. The latter contains a naturally occurring monoamine oxidase inhibitor, similar to the compounds found in prescription antidepressants. Put the two together, and you’re in for a mind-altering experience.
One of the best-known religious groups to use the tea is União do Vegetal, or UDV. Its ceremonies usually last for several hours and are closely supervised by a more experienced member of the church. Participants experience bizarre hallucinations; one described it this way: “Dark creatures sail by. Tangles of long, hissing serpents. Dragons spitting fire. Screaming humanlike forms.”
The experience usually ends with severe vomiting. The vomiting is seen as a kind of purge of psychological problems or demons. People who have participated in the ceremony report that it relieved their depression, cured their addiction, or treated other medical problems. Although there is little clinical evidence to support this, ayahuasca’s similarity to prescription antidepressants has interested some researchers, who have called for more detailed studies.
Lower levels of the Amazon; also found in other parts of South America
The tea also attracted the attention of Jeffrey Bronfman, a member of the wealthy family that founded Seagram, makers of whisky and gin. Bronfman formed a branch of the UDV church in the United States and began importing the tea. In 1999 his shipment was intercepted by U.S. Customs agents, and Bronfman sued to have the tea returned to him. The case landed in the Supreme Court, and in 2006 the court ruled in his favor, allowing the use of the tea for religious purposes. The court’s ruling was based primarily on the Religious Freedom Restoration Act, which Congress had passed in response to an earlier Supreme Court ruling against the use of peyote for religious purposes. According to news reports, the church, known as Centro Espírita Beneficente União do Vegetal, has 130 members and meets at Bronfman’s home in Santa Fe. The U.S. Drug Enforcement Administration continues to enforce the laws against nonreligious use of ayahuasca and other products containing DMT.
“Dark creatures sail by. Tangles of long, hissing serpents, dragons spitting fire. Screaming humanlike forms.”
Meet the Relatives Banisteriopsis Caapi is a member of a large family of flowering shrubs and vines found primarily in South America and the West Indies.
Meet the Relatives Psychotria viridis is a member of the coffee family; relatives include cinchona, the quinine tree, and the poisonous ground cover sweet woodruff, which flavors may wine. Another powerful vine in the same genus is P. ipecacuanha, from which a treatment for plant poisonings, syrup of ipecac, is made.
The betel nut palm rises gracefully to over thirty feet tall on a slim, dark green trunk, sports glossy dark leaves, and produces lovely white flowers that perfume tropical breezes. This palm is also responsible for the betel nut, an addictive stimulant that turns teeth black and saliva red. Four hundred million people around the world consume it.
The custom of chewing betel nuts dates back thousands of years. Seeds from 5000 to 7000 BC have been found in a cave in Thailand, and a skeleton from 2680 BC was found in the Philippines with teeth stained by the juice of the betel nut.
Betel palm, areca, pinang
Like coca, the betel nut is stashed between the cheek and gum and is usually mixed with a little something extra to give it a kick. In India thin slices of the nut are wrapped in a fresh betel leaf with some slaked lime (calcium hydroxide extracted from ashes), a few Indian spices, and sometimes tobacco. The betel leaf used for the outer wrapping is the leaf of Piper betle, or “betel” vine, a low-growing perennial whose leaves are also a stimulant. In fact, the betel nut palm gets its name from its association with this unrelated, but synergistic, plant.
This packet of leaf and nut, often called a quid, has a bitter, peppery taste, and it releases alkaloids similar to nicotine. Users get an energy boost, a mild high, and more saliva than they know what to do with.
There’s only one way to handle the constant flow of red saliva from your mouth when you chew betel: spit it out (swallowing causes nausea). In countries where betel nuts are popular, the sidewalks are stained with red saliva. If this sounds unpleasant, consider poet and essayist Stephen Fowler’s description: “There is an almost orgasmic satisfaction to be found in the experience of saliva-ducts open to full throttle. Delicious above all is the aftermath: when the chew is finished, your mouth is left astonishingly fresh and sweet. You feel uniquely cleansed, drained, and purified.”
There’s only one way to handle the constant flow of red saliva from your mouth when you chew betel: spit it out.
The betel nut is enjoyed throughout India, Vietnam, Papau New Guinea, China, and in Taiwan, where the government is trying to crack down on “betel nut beauties,” scantily clad women who sit in roadside stands and sell their products to truck drivers.
In addition to its addictive qualities—withdrawal symptoms include headaches and sweats—regular chewing of betel nuts leads to an increased risk of mouth cancer and may also contribute to asthma and heart disease. The use of betel is largely unregulated around the world, and public health officials worry that it could rival tobacco as a serious health threat.
Meet the Relatives The betel nut palm is perhaps the best-known member of the Areca genus, which contains about fifty different species of palms. Its partner in crime, Piper betle, is related to P. nigrum, the source of black pepper, and P. methysticum, source of the mellow herbal supplement kava.
One autumn morning in 1978, communist defector and BBC journalist Georgi Markov walked across London’s Waterloo Bridge and stood waiting at a bus stop. He felt a painful jab in the back of his thigh and turned around in time to see a man pick up an umbrella, mumble an apology, and run away. Over the next few days, he developed a fever, had trouble speaking, began throwing up blood, and finally went to the hospital, where he died.
Warm, mild winter climates, rich soil, sunny areas
Eastern Africa, parts of western Asia
Palma Christi, ricin
The pathologist found hemorrhages in almost every organ in his body. He also found a small puncture mark on Markov’s thigh and a tiny metal pellet in his leg. The pellet contained ricin, the poisonous extract of the castor bean plant. Although KGB agents were suspected of the crime, no one has ever been charged with the infamous “umbrella murder.”
Castor bean is a dramatic annual or tender perennial shrub with deeply lobed leaves, prickly seedpods, and large, speckled seeds. Some of the more popular garden varieties sport red stems and splashes of burgundy on the leaves. The plant can reach over ten feet tall in a single growing season and will grow into a substantial bush if it is not killed by a winter freeze. Only the seeds are poisonous. Three or four of them can kill a person, although people do survive castor seed poisoning, either because the seeds aren’t well chewed or because they are purged quickly.
Although KGB agents were suspected of the crime, no one has ever been charged with the infamous “umbrella murder.”
Castor oil has been a popular home remedy for centuries. (The ricin is removed during the manufacturing process.) A spoonful of the oil is an effective laxative. Castor oil packs are used externally to soothe sore muscles and inflammation. It’s also used in cosmetics and other products.
But even this natural vegetable oil is not entirely benign: in the 1920s Mussolini’s thugs used to round up dissidents and pour castor oil down their throats, inflicting a nasty case of diarrhea on them. Sherwood Anderson described the castor oil torture this way: “It was amusing to see Fascisti, wearing black shirts and looking very earnest, bottles sticking out of their hip pockets, chasing wildly down the street after a shrieking Communist. Then the capture, the terrible assault, hurling the luckless Red to the sidewalk, injecting the bottle into his mouth to the muffled accompaniment of blasphemy of all the gods and devils in the universe.”
Meet the Relatives The garden spurge called euphorbia, known for its irritating sap; the poinsettia, also mildly irritating but, contrary to rumor, not dangerous; and the rubber tree, Hevea brasiliensis, source of natural rubber, are all related to the castor bean.