Poisonous plants in the nightshade family


New potatoes, delicious cherry tomatoes, hot chilies and the eggplant essential for the moussaka – all are they members of the nightshade family Solanaceae. The nightshade family has a lot more to offer than culinary delicacy. Plants such as henbane and nightshade have through their hallucinogenic effects been strongly associated with witches flying on brooms.

Potatoes in fashion

Potatoes played a part in 18th century fashion. As powder for the imaginative wigs of the time, large quantities of wheat flour was used, at the same time as people were starving. Using potato flour for the wigs and saving the wheat flour for bread became a solution to the problem.

Medicine or poison?

Numerous species of the family give us medicines or are harmful to us. Many are lethal. If something is curative or poisonous is above all a question of dosage.

Many modern pharmaceuticals originate from the world of plants. Far from all substances can be completely synthesised chemically, sevral are still extracted from plants.

Many plants contain a wide array of different chemical compounds; one might well have desired medical properties, while others could have unwanted effects. Furthermore, knowing the amount of an active substance in a plant at a given moment is very difficult.

To consume medicinal plants could be very dangerous or even fatal. It is advantageous to extract and manufacture active substances in a laboratory where you could control purity and concentration.

What is a poison?

There is no completely unambiguous definition, but generally poisonous substances are harmful to living organisms. The dosage is very important. Many pharmaceuticals can be fatal if you take too much of them.

“All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison.” Paracelcus (1493-1541)

Why are plants poisonous?

Plant poisons are originally the results of mutations in the plant DNA. If they are beneficial to the plant, e.g. by making herbivores avoid eating the plant, natural selection will act on it. Eventually the trait that contributed to the synthesis of the poison will spread through the population.

Strong or unpalatable tastes work in the same way. There are plant species that produce more poison if they are grazed - an ingenious way to save resources!


Chilies and peppers are hot cultivars of the same species as bell peppers, that is their fruits contain more of the compound capsaicin.

Apart from producing fruits up to million times hotter than bell pepper, capsaicin from chilies are used in analgesics. It reduces for example pain caused by post-herpetic neuralgia, an ongoing nerve pain that might develop after shingles.

Because capsaicin causes severe pain in contact with skin, eyes, and mucous membranes, it is an ingredient in pepper spray. In Sweden, you need a firearm licence to use such a spray. A spray for riot control or personal defence has a strength of circa 5 million scoville (bell peppers have 0 – 100, the record holder ‘Carolina Reaper’ has circa 2 million, and pure capsaicin 16 million).


No smoking-signs and warning texts are clear – smoking is lethal.

1 ½ billion people use tobacco regularly. Over 8 million die yearly due to tobacco. Tobacco gives a sense of well-being because the neurotransmitter noradrenaline is released, but heart and lungs are affected negatively and the pulse and blood pressure are raised. These effects are mainly due to nicotine. Nicotine is highly addictive. 50 milligram nicotine per kilogram of body weight is lethal; that is about the amount of nicotine in five cigarettes (but most of it is destroyed by the heat or is not inhaled).

The poison is the plant´s protection against herbivores. Nicotine is also present in potato and tomato, but in much lower concentration.


Many of you have read about Harry Potter. In his magical world, there are mandrakes with deadly screams. Mandrake has a long history as a magical and medicinal plant. It contains similar hallucinogenic compounds as the ones in henbane and belladonna.

The root looks like a naked human body and has been dressed in clothes and used as a lucky charm. Since one can die from the plant´s screams while collecting it, a black dog was tied to the plant and the dog’s life was risked instead of one’s own. This should preferably be done at midnight at a gallows hill, where the most potent roots grew out of a hanged man’s seed.

It was important to sell a bought lucky charm before one died, cheaper than one paid for it – otherwise eternal pain was awaiting.


With its large trumpet-shaped flowers, the angel trumpet attracts both gardeners and its pollinating moths. But be cautious! Since the plant contains the poison atropine, ingestion can lead to mouth dryness, facial redness, palpitations, vertigo, enlarged pupils, blurred vision, uneasiness, anxiety, hallucinations, muscle disorders, and unconsciousness.

Several cultures in South America have used the hallucinogen angel trumpet and close relatives in religious ceremonies. Shamans often used them as a means of inducing trance, thus being able to interact with the spirit world.


In Venice, during the Renaissance, beautiful women (bella donna = beautiful woman in Italian) used belladonna to become even more attractive. The compound atropine in the plant enlarges the pupils in a supposedly seductive way. Today this effect has become useful in operations of the eye.

Atropine moderates the parasympatic nervous system and has many medical uses, for example against slow heart rate. It has also been used as an antidote against nerve agents.

High doses of atropine is hallucinogenic, causes rage, and might lead to unconsciousness or eventually death.

The Greek goddess Atropos is one of the three Fates, she who cuts off the thread of life and thereby ending one’s life.


Henbane, a hallucinogen as it is, was allegedly used by witches to be able to fly on their brooms to places where to dance with the Devil.

The seeds give away a hallucinogen smoke if put on fire. Linnaeus tells that hen-thieves placed seeds of henbane in their pipes and smoked near the hens in order to stun them. Thus, they could be caught without screaming.


The common name comes from the spiny fruits. The trumpet-shaped flowers are white to purple. If one rubs the leaves, they give away a scent reminding of peanuts.

Just like the hallucinogen “witch plants” henbane, scopolia, and belladonna, thornapple contains atropine and scopolamine. Scopolamine have similar properties as atropine, but also moderates the central nervous system and is therefore used against motion sickness and often together with morphine before operations. It has also been used as a truth serum.