Search Results for: plants that kill

Plants That Kill: Neem Tree

Adapted from page 217 of Plants That Kill:

Neem, also known as Indian neem, is grown across the tropics and subtropics as a shade tree, for reforestation programmes and in plantations for production of azadirachtin, but is considered invasive in parts of Africa, the Middle East and Australia, where it has become naturalized. The seeds of Philippine neem (Azadirachta excelsa), which is native to Indonesia, Malaysia, Philippines, Papua New Guinea and Vietnam, and has naturalized in Singapore and Thailand, are also a source of neem insecticides. However, even though neem-based pesticides are a good biological alternative to synthetic compounds, accidental ingestion of neem products or seeds has resulted in a number of deaths, especially in children.

While the effectiveness of neem insecticides is directly associated with azadirachtin content, the biological activity of many of the other compounds present in the neem tree (most of which are also triterpenoids of the limonoid group) add to its effect. Used in their natural combination, they may be helpful in mitigating the development of pesticide resistance.

The neem tree (Azadirachta indica) can reach 10–20 m (30–65 ft) in height. It has compound leaves with several pairs of leaflets and heads of 150–250 small white flowers. Photo credit: QpicImages, Alamy Stock Photos

The antifeedant activity of azadirachtin and some of the other neem compounds is through their stimulation of specific ‘deterrent’ cells on the insect mouthparts, while blocking other receptor cells that normally stimulate feeding, resulting in starvation and death of the insect. Insects vary considerably in their behavioural responses to azadirachtin. Studies on the desert locust have shown that it has a particularly high sensitivity to azadirachtin as an antifeedant, being deterred from feeding at concentrations of 0.04 parts per million. Interestingly, North American grasshoppers, including the American grasshopper (Schistocerca americana), which is in the same genus as the desert locust, are insensitive to azadirachtin at such low concentrations. 

Insects that are not deterred from feeding on azadirachtin do not die immediately, but soon stop eating due to the action of the compound on a number of physiological pathways. It interferes with moulting and growth, for example, by blocking production and release of moulting hormones, causing moulting defects, and it disrupts reproduction by reducing the number of viable eggs and live progeny. 

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

 

Plants That Kill: Ephedera

Adapted from page 214 of Plants That Kill:

The drug ma huang has been one of the most important in the Chinese materia medica for millennia, having been first recorded in Shen-nung Pen-ts’ao Ching (Divine Husbandman’s Materia Medica), the earliest extant Chinese pharmacopoeia (c. ad 25–200). Today, it is sourced from four species of ephedra (Ephedra spp.), including E. sinica, which is native to northeast China, Mongolia and parts of Russia. In fact, at least two-thirds of Ephedra species from across the globe are used medicinally, and are the source of useful compounds in the fight against cold and flu symptoms. Unfortunately, however, they are also subject to abuse.

Chinese ephedra (Ephedra sinica) is a gymnosperm and close relative of conifers, including yews (Taxus spp.). The stems are photosynthetic and the fruit are fleshy cone bracts. Photo credit: WILDLIFE, Alamy Stock Photos

The small genus of Ephedra contains around 54 species within its own family, Ephedraceae, distributed in northern temperate regions of the world as well as in western South America. There is evidence that ephedra may be one of the first plants that was used medicinally, as pollen of medicinal plants, including high-climbing jointfir (E. altissima), was found in the grave of a male Neanderthal buried in Shanidar Cave, Iraq, in around 60,000 bc. Some scientists dispute the interpretation that flowers had been placed deliberately in the grave, however, as the pollen may have been introduced by burrowing rodents. 

Indisputable recorded uses of ephedra in traditional medicine systems include the treatment of asthma, hay fever and other allergies, as well as respiratory diseases such as bronchitis, emphysema, and colds and influenza. The effectiveness of ephedra in treating many of these conditions is not in doubt, but abuse of the active compounds has required their use today to be controlled. 

Ephedra species contain several alkaloids: ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine (cathine), methylephedrine and methylpseudoephedrine. Levels vary tremendously between the species (the North American species Nevada ephedra (E. nevadensis) is apparently devoid of them) and also between plant parts, with the alkaloids concentrated in green stems and leaves, while fruits and roots have virtually none. 

Ephedrine and related alkaloids stimulate the nervous system by mimicking the effects of compounds naturally produced by the body that bind to and activate receptors (endogenous agonists). They are potent stimulators of receptors that are targets for adrenaline (epinephrine) and noradrenaline (norepinephine), and responsible for the ‘fight or flight’ response. The effects of these drugs include constriction of blood vessels (vasoconstriction), raised blood pressure, increased heart rate, expansion of bronchial tubes (bronchodilation), which makes breathing easier, and increase in energy expenditure (thermogenesis). 

The two major alkaloids found in Ephedra species, ephedrine and pseudoephedrine, have been used in decongestant medicines to treat coughs, colds and sinusitis. However, these alkaloids are structurally similar to synthetic amphetamines, with ephedrine differing from methamphetamine only in a hydroxyl group, leading to the use of these medicines in the illicit manufacture of amphetamines. In response, restrictions are generally in place on the sale of products containing the alkaloids. In the United Kingdom, for example, they can legally be sold only at pharmacies, by or under the supervision of a pharmacist, with permitted levels of the alkaloids kept to a minimum if sold without a prescription. 

Restrictions also apply to the sale of the herbal ephedra drug ma huang and others, which have been marketed as ‘herbal ecstasy’. Despite these legal restrictions, the raw herb and products containing ephedra and its alkaloids are still openly sold over the Internet, posing a potential risk to consumers who are unaware of the extremely dangerous side effects.

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

 

Plants That Kill: White Snakeroot

Adapted from page 191 of Plants That Kill:

When Europeans started to settle in the Midwest region of the United States in the 1800s, they and their livestock began to fall ill. The animals developed violent trembling when they were forced to move or became agitated, and the disease became known as trembles. People who drank the milk of affected animals developed so-called milk sickness, and it is estimated that in some areas of Indiana and Ohio 25–50 per cent of the deaths of early settlers were caused by this condition. One casualty in 1818 was Nancy Hanks Lincoln, whose son, nine years old at the time, would become President Abraham Lincoln. 

Nowadays, human poisoning by white snakeroot (Ageratina altissima) is rare due to industrial milk production, but it is an historically interesting killer plant. Photo credit: Shutterstock, Wiert nieuman

It took some time to identify white snakeroot (Ageratina altissima, syn. Eupatorium rugosum) as the cause of trembles. Although the plant was initially suggested as the culprit in the 1830s, this was only confirmed in the early 1900s. This member of the daisy family (Asteraceae) grows in moist, shaded areas, such as along stream beds and near tree lines. Animals do not show any signs of being poisoned until they have been eating white snakeroot for one to three weeks, and symptoms finally progress to chronic degeneration of the skeletal muscles. Benzofuran ketones, including tremetone, are at least partly responsible for the toxicity of white snakeroot, and they are also found in another member of the daisy family, the rayless goldenrod (Isocoma pluriflora, syn. Haplopappus heterophyllus), which causes a similar disease in grazing animals. 

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

 

Plants That Kill: Cycads

Adapted from pages 188-189 of Plants That Kill:

The cycads are a group of slow-growing tropical and subtropical palm-like trees that have barely changed since before the time of the dinosaurs – cycad fossils date back to the Late Palaeozoic era, 290–265 million years ago. Their resistance to hurricanes and droughts is part of the reason for their continued survival to the present day. Over the centuries, humans have used cycads for food and medicine, but the toxins they contain mean they have to be processed before they are consumed. Even then, there can be long-term consequences.

Crown of the sago cycad (Cycas revoluta), with a head of developing seeds attached to small leaf-like structures, and surrounded by rigid palm-like leaves up to 1.5 m (5 ft) long. Photo credit: Shutterstock, JT888.

The sago cycad (Cycas revoluta), a member of one of the two families of cycad (Cycadaceae, the other one being Zamiaceae), is often called the ‘sago palm’ but should not be confused with the true sago palm (Metroxylon sagu) in the palm family (Arecaceae). Native to Japan, it is probably the most widely cultivated cycad. Various parts of this and other cycads are eaten by humans, usually when other crops have been destroyed by natural disasters or as a stop-gap during seasonal shortages, but also as a staple part of the traditional diet in many regions. The young leaves may be eaten as a vegetable, but it is the seeds and also the stem pith that are most often used as they, after a long detoxification process, provide a flour with a high starch content.

When Europeans first encountered cycads during their voyages of discovery, they were unaware of their toxicity. During Captain James Cook’s first voyage to Australia in 1770, the botanist Joseph Banks noticed that several crew members became violently ill after eating nuts from Cycas media, and General Jan Smuts and his troops fell foul of the breadpalm (Encephalartos longifolius, Zamiaceae) during the Boer War. In Honduras, it has been documented that the roots of camotillo (Zamia furfuracea, Zamiaceae) were used in unlawful poisonings. Improper processing of cycad plants before consumption, either as a food or traditional remedy, leaves the azoxymethanol glycosides they contain at toxic levels and is now the usual cause of acute poisoning. A second toxin, beta-methylamino-L-alanine (BMAA), which is particularly concentrated in the seeds and root nodules, is not removed by the processing, but only takes effect if the plant is eaten on repeated occasions. 

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

Plants That Kill: Ackee

Adapted from pages 158-159 of Plants That Kill:

Although it has also been introduced to the other Caribbean islands, Central America and Florida, ackee is widely eaten only on Jamaica. In fact, it is Jamaica’s national fruit, and ackee and saltfish is the national dish. The leathery fruit are 7.5–10 cm (3–4 in) long, bright red or yellow-orange when ripe, and split open into three sections to expose three shiny black seeds, each surrounded by a large yellow or whitish aril. Only arils from ripe fruit that have naturally split open are eaten. To remove any residual toxicity, they are cleaned of all red fibre (the aril membrane) and boiled, and the water they are boiled in is discarded. Cooking unripe arils does not destroy their toxicity.

The ackee tree (Blighia sapida) has pairs of glossy leaves. Its fruit ripen to red and, when they split open, the cream arils within can be eaten after cooking.
Photo credit: Shutterstock, twiggyjamaica

Before the toxicity of ackee was understood, eating unripe arils frequently caused poisoning known as Jamaican vomiting sickness, which occurred as an annual epidemic. Symptoms included vomiting, convulsions and, frequently, also coma and death, with mortalities being more common in children, particularly those already suffering from malnutrition. The underlying cause was eventually linked to the consumption of unripe ackee arils. This results in low blood sugar levels (hypoglycaemia) through a blockade of the liver’s ability to synthesize glucose and a reduction in fatty acid metabolism (both normal routes for increasing levels of blood sugar), as well as depletion of the liver’s carbohydrate reserves. 

Poisoning is due to the presence of an amino acid derivative, hypoglycin A (2-amino-3-(methylenecyclopropyl)- propionic acid), which is also found in other plants of the soapberry family, such as lychee (Litchi chinensis). In ackee, the concentration of hypoglycin A is high in unripe arils and reduces significantly as they ripen, although low levels remain in the aril membrane. The seeds also contain the less toxic hypoglycin B (the gamma-glutamyl conjugate of hypoglycin A), with concentrations significantly increasing as the seeds ripen. 

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

 

Plants That Kill: Capsaicin

Adapted from pages 122-123 of Plants That Kill:

The fruit and seeds of species of chilli peppers (Capsicum spp.) in the potato family (Solanaceae) contain a pungent compound, capsaicin, that makes food ‘hot’. As well as being used by humans as a spice for thousands of years, capsaicin also has medicinal applications, and the burning discomfort and pain it causes have found roles in riot-control and self-defence. 

The chilli or chili pepper (Capsicum annuum) is a small shrub from Mexico and Guatemala, with simple leaves and pendant, star-shaped flowers that appear singly and are followed by elongated, brightly coloured fruit. Numerous cultivars have been bred that vary in the size, shape and pungency of these fruit. They include the large, sweet bell peppers, as well as mild to hot chilli peppers. The taxonomy of chillies is complicated, however, with some cultivars of C. annuum having characteristics that overlap with those of two other species, the Tabasco pepper (C. frutescens) from Bolivia and western Brazil, and the very hot bonnet pepper (C. chinense), which despite its specific epithet is from Bolivia, northern Brazil and Peru. Some prefer to treat these three species and their cultivars as the ‘annuum–chinense– frutescens complex’. 

To alleviate the ‘heat sensation’ from chilli, try eating a yogurt raita containing chopped mint (Mentha spp.) leaves, as the menthol from the mint stimulates ‘cold sensation’ neurons. Photo credit: one photo, Shutterstock

Some culinary traditions use more chilli pepper than others, with the highest number being eaten in the species’ native Mexico (one chilli per person per day). Chilli has also been embraced in many of the countries to which it has been introduced, particularly India, where it is a key ingredient in curries, and Thailand. Either the fresh fruit and seeds, or the powdered or flaked dried fruit, are used for seasoning during cooking or as a condiment. 

The pungent compounds in chilli peppers, including capsaicin (8-methyl-N-vanilloyl-6-nonenamide), are capsaicinoid alkaloids, which bind to vanilloid receptors on sensory neurons (known as transient receptor potential vanilloid (TRPV) channels). These same receptors can also be stimulated by heat and pain, so the binding of the capsaicin results in the sensation of heat. The degree of burning and reddening is related to the concentration of capsaicinoids (see box) and duration of exposure (a dose-related response). TRPV channels are common to all mammals, and thereby deter rodents and other mammalian pests from eating chilli crops. Birds lack the capsaicin-binding site of these channels, however, so eat the ripe red fruit and disperse the seeds without harm. 

In addition to the sensation of heat and burning in the mouth, eating large amounts of hot chillies can cause irritation of the gastrointestinal tract. It is the burning discomfort and pain that chillies or concentrated chilli extracts cause to the eyes and nose that can be most distressing. Pepper sprays have proved to be effective weapons since they were first employed by Mayan Indians, and police forces in a number of countries now use them in the control of unruly individuals and crowds. However, the legality of using pepper sprays for self-defence varies around the world. 

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

 

Plants That Kill: The Little Apple of Death

Adapted from page 118 of Plants That Kill:

The manchineel tree is found from the coast of Mexico south through Central America to Colombia and Venezuela, as well as in the West Indies and Florida. Its caustic properties soon became known to European explorers of the New World, who encountered the tree on beaches. In the sixteenth century, Oviedo noted its danger in his book on the natural history of the West Indies (which incidentally also included the first illustration of a pineapple): 

It has been proved many times that if men carelessly lie down to sleep under the trees, when they rise after a short nap there is a great pain in the head and swelling of the eyes and cheeks. And if by chance the dew from the tree falls on the face, it is like fire, blistering and burning the skin wherever it touches; and if it falls in the eye it blinds or burns them, and the sight is endangered. If the wood is burned no one can endure it long, for it causes much heaviness, and such headaches that all stand away from it, be they man or any other animal.

Leafy branches and immature fruit of the manchineel (Hippomane mancinella), also known as manzanita de la muerte, literally ‘little apple of death’, are a risk for unwary visitors to tropical beaches. Photo Credit: Rob Matthews, Alamy Stock Photo

Since then, numerous graphic accounts of the symptoms that result from skin or eye contact with the latex of the manchineel tree have been published, so we can be left in no doubt of the harm the species can cause. In addition, it produces deceptively apple-like fruit, which are 3–5 cm (1–2 in) in diameter, and when ripe are yellowish green with flushed red cheeks and an aromatic, pleasant-tasting yellow flesh. These, too, can cause contact reactions, and eating the fruit is even more disastrous, as doing so irritates the mouth, throat and digestive tract; deaths have occurred.

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

Plants That Kill: Deadly nightshade, black henbane & witchcraft

Adapted from page 81 of Plants That Kill:

Deadly nightshade (Atropa bella-donna) is a herbaceous perennial that dies back to a rootstock every year but can grow into a substantial plant during the summer. Attractive, juicy black berries follow its solitary bell-shaped purplish flowers, and conspicuous green sepals form a star at the base. Deadly nightshade grows naturally in Europe, west Asia and north Africa. In northern Europe it is particularly found on chalky soils and close to former abbeys and monasteries, where it was grown as a medicinal plant during the Middle Ages.

Black henbane (Hyoscyamus niger) is native to much of Eurasia and is now widely distributed in temperate regions. Photo credit: A_lya, Shutterstock.

Deadly nightshade is just one of the tropane alkaloid-containing plants that are inextricably linked to tales of witchcraft. Together with mandrakes (Mandragora spp.) and henbane (Hyoscyamus spp.), it is said to have been an ingredient of an ointment used by witches to give them the sensation of flying, and is why witches are often depicted on broomsticks. 

One of the most recent deaths from deadly nightshade, of which there are actually very few, was of a modern-day witch who went by the name of Robert Cochrane. He lived in Slough, United Kingdom, where he started a coven known as the Clan of Tubal Cain, based on a combination of Celtic mysticism and village witchcraft philosophy (American branches are known as the ‘1734 tradition’). Cochrane died nine days after the eve of the summer solstice in 1966, seemingly after having ingested deadly nightshade leaves and sleeping tablets. The inquest into his death returned a verdict of suicide with deadly nightshade. In some witchcraft circles it is believed that Cochrane had appointed himself as a male sacrifice.

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

 

Plants That Kill: Apocynaceae

Adapted from page 52 of Plants That Kill:

The dogbane family is one of the larger families of flowering plants, and is today considered to contain more than 5,000 species in 366 recognized genera, including those that have, at times, been placed in their own family, Asclepiadaceae. The almost globally distributed Apocynaceae (only northern regions lack native species) has adapted to almost all environments and contains a large diversity of plant forms. 

Species grow as herbs, climbers and lianas, succulents or trees. The flowers are often showy or conspicuous in form or smell, and many species have evolved special structures for pollen dispersal, such as pollinia, coherent masses of pollen grains that are transferred to the next plant by sticking to insect pollinators. These structures are especially elaborate in milkweeds (Asclepias spp.), waxflowers (Hoya spp.) and their relatives, constituting a feature that allows easy placement of these plants within the family (although deciding on the actual genus and species can be quite difficult).

Elephant vine (Strophanthus amboensis) is found from Zaire to Namibia and contains cardioactive steroids. The petals are fused to form a cup at the base and there are five spreading, elongated lobes.

The large number of species and wide geographical distribution of the dogbane family makes it easy to understand why so many plants are used by humans. The showy, waxy flowers of frangipani (Plumeria spp.) have found a place as a constituent in Polynesian lei garlands, the fibres from dogbane (Apocynum cannabinum) have been used to make cloth and string, some species are used in religious rituals, and some genera, such as Landolphia, were briefly important as sources of rubber in the late nineteenth and early twentieth centuries. Several plants in the family have been used as arrow poisons or in traditional medicinal systems, and the Madagascar periwinkle (Catharanthus roseus) is the source of an important cancer drug. 

It seems that most plants in the dogbane family are toxic to some degree, but the reason for this differs between groups of species. Some groups produce cardioactive steroids as the toxic principle, while others produce monoterpene indole alkaloids. Accordingly, the family presents several toxidromes, the combined picture of symptoms in poisonings, with some presenting as acute heart failure with arrhythmias and others giving signs of detrimental effects on the nervous system – for example, seizures, paralysis and hallucinations. As members of the dogbane family are widely distributed and many produce fatal intoxications, the use of these plants in suicides and poisonings is not uncommon in certain regions of the world.

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

Plants That Kill: Aconite alkaloids

From hemlock and deadly nightshade to poppies and tobacco, poisonous plants have long been used in medicine, rituals, and even warfare. For the next few months, Princeton Nature will be taking a closer look at the evolution, survival strategies, physiology, and biochemistry of the most toxic plants on Earth. Pulling from Elizabeth A. Dauncey & Sonny Larsson’s new book, Plants That Kill, we hope to provide you with just a sample of the deadly and intriguing plants that can be found in this gorgeously illustrated book.

Adapted from page 48-49 of Plants That Kill:

Aconite alkaloids are mostly restricted to a small number of genera in the buttercup family, particularly the aconites (Aconitum spp.) and their close relatives the larkspurs (Delphinium spp.). The presence of the compounds seems to give these plants a strong evolutionary advantage, as the group constitutes about a third of all species within the family. Aconites and larkspurs produce these highly toxic compounds from a substance called geranylgeranyl diphosphate, which is an essential part of the chlorophyll needed for photosynthesis. They can be grouped into three different ‘flavors’, called veatchine, atisine and aconitine alkaloids. The compounds in the last of these groups are the most toxic, which is thought to be due to their ability to pass through fat-containing barriers such as cell membranes and also the skin. This explains why gardeners and florists who, with bare hands, handle the cut stems or crushed material of aconite and larkspur plants in large amounts or for extended periods of time may experience mild symptoms of tingling or numbness.

There are around 250 species of aconite (Aconitum spp.) found in the wild in the northern hemisphere, but they are also widely grown in temperate gardens and sold as cut flowers.                              Photo credit: Alex Polo, Shutterstock

Species of aconite are used to treat joint pain in traditional Chinese herbal medicine in the form of bath additives, rubs and ointments. Their alkaloids can be absorbed through the skin, where they act as local anaesthetics. They may also be taken orally to treat asthma, gastroenteritis and various tumours, or as a supportive and revitalizing tonic. How is this possible, when these plants are very poisonous and small amounts can cause dangerous, or even lethal, effects on the heart and respiratory muscles? 

Before use, the raw material must be subjected to pao zhi (a detoxifying measure), which might include heating and/or soaking with the intention of ensuring maximal therapeutic efficacy with minimal adverse effects. During such processes, the toxic alkaloids are transformed into less harmful compounds, explaining why aconite use has persisted in spite of its high risk of poisoning. However, even though pao zhi is usually performed, a number of patients who take traditional Chinese aconite medicines are hospitalized each year due to poisoning. 

Plants That Kill: A Natural History of the World’s Most Poisonous Plants
By Elizabeth A. Dauncey & Sonny Larsson

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays. This intriguing book also looks at plants that can harm you only if your exposure to them is prolonged, the ethnobotany of poisons throughout human history, and much more.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

  • Provides an authoritative natural history of the most poisonous plants on earth
  • Features hundreds of color illustrations throughout
  • Looks at how and why plants produce toxins
  • Describes the effects of numerous poisonous plants, from hemlock and deadly nightshade to poppies and tobacco
  • Explains poisonous plants’ evolution, survival strategies, physiology, and biochemistry
  • Discusses the uses of poisonous plants in medicine, rituals, warfare, and more

 

Elizabeth A. Dauncey & Sonny Larsson on Plants That Kill

Have you ever wondered which are the most poisonous plants in the world, why they produce toxins, and what those toxins are? Are you interested in the ingenious ways that humans have found to exploit these plants for good or evil? Plants That Kill, a new, beautifully illustrated, popular science book provides the answers.

Authors Elizabeth A. Dauncey and Sonny Larsson met when they were both working as scientists at the Royal Botanic Gardens, Kew, in London, and have now combined their experience and expertise in the botany and chemistry of poisonous plants and their toxicity to animals to write an informative and engaging book that gives you the facts.

Why did you write the book?

ED: When the chance arose to introduce this fascinating aspect of plants to a worldwide popular science audience, I just couldn’t resist. Plants are essential to the survival and wellbeing of humans and animal life in general and this book is a way of engaging with the public and showing them that plants are interesting. Also, poisonous plants always make a good news story (not a good-news story) and this book was an opportunity to present more fact-based information that is still entertaining. It might dispel a few myths and definitely includes more than a few surprises.

SL: How could I say no to an opportunity to explain how and why plants produce compounds that are poisonous? Its just a great subject! I never cease to be amazed by the sheer variety of chemicals that plants produce and the numerous mechanisms by which they can cause harm. I also think the book provides an opportunity to get people curious about new aspects of the subject regardless of whether one’s particular interest is in plants, poisons or ecology.

Who is this book aimed at?

ED: Anyone interested in how plants or nature works, such as people with an academic or general interest in biology or chemistry, the natural world more broadly or man’s interaction with it. We couldn’t avoid including some rather long names of chemicals and the scientific names of plants, but people shouldn’t be put off by these as the rest of the text has been written to be accessible.

SL: The plants are the focus and center of attention in this book, so it is for anyone curious about how poisonous they can be, or their natural history more widely. I actually think everyone will get something out of reading this book — in the end the subject is a mix of science and human-interest stories.

What makes this book special or different?

ED: Plants That Kill really is one of a kind. Its uniqueness is to bring together in one package a global survey of the most harmful plants (particularly those that have killed humans and other large animals), describing the toxins that they produce and exploring their effects illustrated by interesting cases of poisoning. We’ve chosen to organise the plant toxins, and the plants that contain them, according to the part of the body that they affect most, which is an unusual but useful way of approaching the subject.

SL: I think what sets the book apart is our handling of the chemistry of poisonous plants within a biological framework — you’ll not only learn about the toxin and how it works on the animal body, but for many substances we also give examples of its role within the plant.

How did you decide which plants to include in the book?

SL: The book is intended to present the most poisonous plants from around the world, but there are so many plants that are potentially deadly that finding a fitting selection of actual killers took some deliberation. We didn’t want to restrict the book to only those plants that have killed humans, but broadened the scope to include other animals whose death might evoke at least some sympathy — very few people would miss a mould or a microscopic worm, but they would notice the demise of an elephant.

ED: To draw up our list of potential plant candidates, we consulted books about poisonous plants from around the world and research papers on particular topics such as arrow poisons. From each we picked out the most poisonous ones and then grouped them by the toxins that they produce. The final selection of plants was easy for some, such as the castor oil plant whose seeds contain ricin, a highly toxic plant protein. For others, the toxin group was clearly important but the particular plant or plants to feature was less obvious. Those took more research looking for the deadliest examples and weighing up the evidence to decide which one should be highlighted rather than another.

You’ve included a chapter on medicinal plants, why?

SL: I think it is important to put the concepts of “poisonous plant” and “toxin” into perspective, and giving examples of plants containing really dangerous compounds that we are now using as drugs fighting disease is a very good way of doing that.

ED: In addition to the chapter, we’ve actually included medicinal uses of plant toxins throughout the book. It provides balance to the description of a plant’s toxicity and illustrates how humans have adapted this for their own benefit. Many killer plants really are far more useful to man than dangerous and that’s an important thing to mention.

Did you learn anything new while you were writing Plants That Kill?

SL: So much! Even though I used to teach pharmacognosy and now work at a poison information center, the emphasis has been on local plants and in Sweden we have very few representatives of the really dangerous ones growing in the wild. Reading up on poisonous plants from all over the globe introduced new hazardous substances, species of exotic (at least to me) plant families and stories from cultures far away.

ED: Yes, taking time out to review the latest literature across the board meant that there were plants, toxins and circumstances of poisoning that were completely new to me too. We treated such novelties with the same evidence-based scientific approach to researching that we used for the more familiar plants and toxins, so I’ve learnt a lot during the process of writing, particularly around the chemistry and the mechanisms of toxicity. It was absolutely fascinating and absorbing, which I hope is reflected in the finished book.

Do you have a favorite plant or toxin?

ED: I’d choose a plant family, the carrot family — also known as the Apiaceae or Umbelliferae. Most members of the carrot family can be easily recognised by the structure of their heads of flowers, which form umbels (imagine an umbrella with the canopy formed from clusters of small, usually white, flowers). It gives us root vegetables such as carrots and parsnips, and we happily eat the green parts and seeds of celery and herbs like fennel and coriander. But amongst these wonderful food species lurk some of the most poisonous plants in the world. Examples include dead man’s fingers and hemlock that can kill if a root or leaves are eaten, whilst giant hogweed can cause severe skin reactions if physical contact is combined with bright UV light, such as you might experience on a sunny day.

SL: I am rather partial to colchicine, which is restricted to the autumn crocus family, the Colchicaceae. It has been used as a medicine for gout and a poison since antiquity, and is an important tool in the study of chromosomes and cell division. The fact that it has a very peculiar chemical structure that took over a century to discover also adds to my fascination.

 

Elizabeth Dauncey is a botanist and taxonomist who for the past 25 years has specialised in poisonous and more recently also medicinal plants. She has also written Poisonous Plants: A guide for parents and childcare providers, which provides the information and tools to assess the risk posed by plants in homes, gardens and the countryside.

Sonny Larsson is a pharmacist and pharmacognosist who for almost two decades has studied the connection between plant chemistry and evolution, trying to figure out why and how we can use plants to develop drugs. At the Swedish Poison Information Centre he works as a specialist consultant on plants, herbal drugs and dietary supplements.

The Nature Lover’s Gift Guide for 2018

Do you have a birder in your life, but you just don’t know what to get them this holiday season? Or, are you a nature lover trying to figure out what gifts to ask for this year? Princeton Nature is here to help! Presenting some of our latest titles that would make the perfect present this year — whether you wrap it up for a loved one, or gift it to yourself. 

FOR THE EXPLORER IN YOUR LIFE: Galápagos: Life in Motion by Walter Perez and Michael Weisberg

The Galápagos Islands are home to an amazing variety of iconic creatures, from Giant Tortoises, Galápagos Sea Lions, Galápagos Penguins, and Ghost Crabs to Darwin’s finches, the Blue-footed Booby, and Hummingbird Moths. But how precisely do these animals manage to survive on—and in the waters around—their desert-like volcanic islands, where fresh water is always scarce, food is often hard to come by, and finding a good mate is a challenge because animal populations are so small? In this stunning large-format book, Galápagos experts Walter Perez and Michael Weisberg present an unprecedented photographic account of the remarkable survival behaviors of these beautiful and unique animals. With more than 200 detailed, close-up photographs, the book captures Galápagos animals in action as they feed, play, fight, court, mate, build nests, give birth, raise their young, and cooperate and clash with other species.

Complete with a brief text that provides essential context, this book will be cherished by Galápagos visitors and anyone else who wants to see incredible animals on the move.

Read our Q+A with co-author Walter Perez.

FOR THE BEACHGOER IN YOUR LIFE: Gulls Simplified by Pete Dunne and Kevin T. Karlson

This unique photographic field guide to North America’s gulls provides a comparative approach to identification that concentrates on the size, structure, and basic plumage features of gulls—gone are the often-confusing array of plumage details found in traditional guides.

Featuring hundreds of color photos throughout, Gulls Simplified illustrates the variations of gull plumages for a variety of ages, giving readers strong visual reference points for each species. Extensive captions accompany the photos, which include comparative photo arrays, digitized photo arrays for each age group, and numerous images of each species—a wealth of visual information at your fingertips. This one-of-a-kind guide includes detailed species accounts and a distribution map for each gull.

An essential field companion for North American birders, Gulls Simplified reduces the confusion commonly associated with gull identification, offering a more user-friendly way of observing these marvelous birds.

Check out our Bird Fact Friday spotlights of the birds from Gulls Simplified.

FOR THE ART LOVER IN YOUR LIFE: Stripped Bare by David Bainbridge

For more than two thousand years, comparative anatomy—the study of anatomical variation among different animal species—has been used to make arguments in natural philosophy, reinforce religious dogma, and remind us of our own mortality. This stunningly illustrated compendium traces the intertwined intellectual and artistic histories of comparative anatomy from antiquity to today.

Stripped Bare brings together some of the most arresting images ever produced, from the earliest studies of animal form to the technicolor art of computer-generated anatomies. David Bainbridge draws on representative illustrations from different eras to discuss the philosophical, scientific, and artistic milieus from which they emerged. He vividly describes the unique aesthetics of each phase of anatomical endeavor, providing new insights into the exquisite anatomical drawings of Leonardo and Albrecht Dürer in the era before printing, Jean Héroard’s cutting and cataloging of the horse during the age of Louis XIII, the exotic pictorial menageries of the Comte de Buffon in the eighteenth century, anatomical illustrations from Charles Darwin’s voyages, the lavish symmetries of Ernst Haeckel’s prints, and much, much more.

Featuring a wealth of breathtaking color illustrations throughout, Stripped Bare is a panoramic tour of the intricacies of vertebrate life as well as an expansive history of the peculiar and beautiful ways humans have attempted to study and understand the natural world.

Read our Q+A with David Bainbridge

FOR THE GARDENER IN YOUR LIFE: Plants That Kill by Elizabeth A. Dauncey and Sonny Larsson.

This richly illustrated book provides an in-depth natural history of the most poisonous plants on earth, covering everything from the lethal effects of hemlock and deadly nightshade to the uses of such plants in medicine, ritual, and chemical warfare.

Featuring hundreds of color photos and diagrams throughout, Plants That Kill explains how certain plants evolved toxicity to deter herbivores and other threats and sheds light on their physiology and the biochemistry involved in the production of their toxins. It discusses the interactions of poisonous plants with other organisms–particularly humans—and explores the various ways plant toxins can target the normal functioning of bodily systems in mammals, from the effects of wolfsbane on the heart to toxins that cause a skin reaction when combined with the sun’s rays.

A must for experts and armchair botanists alike, Plants That Kill is the essential illustrated compendium to these deadly and intriguing plants.

Check out our Plants That Kill blog series.

FOR THE SCIENTIST IN YOUR LIFE: Unnatural Selection by Katrina van Grouw

Unnatural Selection is a stunningly illustrated book about selective breeding–the ongoing transformation of animals at the hand of man. More important, it’s a book about selective breeding on a far, far grander scale—a scale that encompasses all life on Earth. We’d call it evolution.

A unique fusion of art, science, and history, this book celebrates the 150th anniversary of Charles Darwin’s monumental work The Variation of Animals and Plants under Domestication, and is intended as a tribute to what Darwin might have achieved had he possessed that elusive missing piece to the evolutionary puzzle—the knowledge of how individual traits are passed from one generation to the next. With the benefit of a century and a half of hindsight, Katrina van Grouw explains evolution by building on the analogy that Darwin himself used—comparing the selective breeding process with natural selection in the wild, and, like Darwin, featuring a multitude of fascinating examples.

Read Katrina van Grouw’s op-ed about her art, as seen in Unnatural Selection.

FOR THE TECH GEEK IN YOUR LIFE: How to Walk on Water and Climb Up Walls by David L. Hu

Insects walk on water, snakes slither, and fish swim. Animals move with astounding grace, speed, and versatility: how do they do it, and what can we learn from them? In How to Walk on Water and Climb up Walls, David Hu takes readers on an accessible, wondrous journey into the world of animal motion. From basement labs at MIT to the rain forests of Panama, Hu shows how animals have adapted and evolved to traverse their environments, taking advantage of physical laws with results that are startling and ingenious. In turn, the latest discoveries about animal mechanics are inspiring scientists to invent robots and devices that move with similar elegance and efficiency.

Hu follows scientists as they investigate a multitude of animal movements, from the undulations of sandfish and the way that dogs shake off water in fractions of a second to the seemingly crash-resistant characteristics of insect flight. Not limiting his exploration to individual organisms, Hu describes the ways animals enact swarm intelligence, such as when army ants cooperate and link their bodies to create bridges that span ravines.

Integrating biology, engineering, physics, and robotics, How to Walk on Water and Climb up Walls demystifies the remarkable mechanics behind animal locomotion.

Check out this video of David L. Hu’s visit to Zoo Atlanta, where he explains animal movement to his children.

AND FOR THE BIRDER IN YOUR LIFE: Birds of Central America by Andrew C. Valley and Dale Dyer

Birds of Central America is the first comprehensive field guide to the avifauna of the entire region, including Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, and Panama. Handy and compact, the book presents text and illustrations for nearly 1,200 resident and migrant species, and information on all rare vagrants. Two hundred sixty detailed plates on convenient facing-page spreads depict differing ages and sexes for each species, with a special focus on geographic variation. The guide also contains up-to-date range maps and concise notes on distribution, habitat, behavior, and voice. An introduction provides a brief overview of the region’s landscape, climate, and biogeography.

The culmination of more than a decade of research and field experience, Birds of Central America is an indispensable resource for all those interested in the bird life of this part of the world.

Read Dale Dyer’s op-ed about what it means to be a nature illustrator.

 

For more titles, browse our Birds & Natural History catalog.