What Plants are Poisonous in the World? – List and Names Curious Answers

Poisonous Plants

Belladonna, one of the deadliest plants in the western hemisphere, is full of toxins. These include atropine and scopolamine; they are anticholinergic and can cause hallucinations, delusions, convulsions, and death.

Poisonous Plants

In fact, taking 2 or more of its berries can kill a child, and about 5 are enough to kill an adult.

The main cause of these effects on the parasympathetic nervous system is the tropane alkaloid called atropine.

This substance is a competitive antagonist, a drug that does not provoke a biological response itself, but blocks or reduces the body’s responses, reducing the activation frequency.

In other words, it makes internal autonomous systems of those who consume stop working, causing semi-paralysis, difficult breathing and making heart rate unstable.

The Brugmansia and Datura Ferox are so poisonous that they were historically used in rituals of intoxication and contain a variety of toxic compounds.

As belladonna, both Brugmansia and Datura Ferox contain atropine and scopolamine; however, due to its wide variety of species, they tend to have more negative effects.

In fact, among the subspecies of each of these two plants, there can be a variation of concentration of toxic substances which can be up to 5 times higher.


The anticholinergic delirium occurs in all overdoses, while tachycardia, severe mydriasis (excessive dilation of the pupils) and short-term amnesia don’t, but they are also common. In the Datura Ferox, higher levels of toxicity can be found in fruits and seeds.

The hemlock is perhaps the most famous mortal plant which contains one of the deadliest neurotoxins naturally produced: Coniine.

It damages the central nervous system, blocking the neuromuscular junctions. This causes muscle paralysis ascending from foot to chest and it finally causes paralysis of the respiratory system leading to death.

In addition to its danger, coniine is very powerful and it is fatal if consumed in slightly higher than 100 mg doses (which are equivalent to 6 leaves or a little less of their roots or seeds).

Death can only be avoided if the person who consumed is connected to a breathing machine until the effects disappear after 72 hours.

The 10 most dangerous poisonous plants in the world


It is so poisonous that simply inhaling its smoke or sawdust causes coughing, laryngitis, and bronchitis.
Symptoms: By contact; blisters, burns, and inflammation (in case of the blindness of the eyes). Swallowed; a sore throat and severe gastrointestinal problems.
Location: This poisonous plant is found mainly in Central America and the Caribbean.
Toxins: hypomaniacs A and B, present in all parts of the tree.


The first European settlers in the New World made the mistake of eating it in 1607, in the settlement of Jamestown. It has been associated with voodoo and witchcraft because of its hallucinogenic properties.
Symptoms: dilated pupils, rapid heart rate, hallucinations, delirium, aggressive behavior, coma, and seizures.
Location: This poisonous plant grows in the Caribbean, the United States and Canada
Toxins: atropine and scopolamine


Just touching it can be dangerous. Nazi scientists used it to poison bullets and shepherds in ancient Greece smeared it with their arrows to kill wolves.
Symptoms: Use causes mouth burns, salivation, vomiting, diarrhea, heart irregularities, coma and sometimes death.
Location: This poisonous plant lives in the mountainous regions of Europe.
Toxin: aconitine. Just 1mg is enough to kill an 80kg adult.


Until the 1920s, it was common for it to cause “milk sickness”, a condition that affected people who drank milk from a cow that had eaten the poisonous plant.
Symptoms: bad breath, loss of appetite, apathy, weakness, vague pain, muscle stiffness, vomiting, abdominal discomfort, severe constipation, coma, and possibly death.
Location: This poisonous plant is native to North America.
Toxin: tremetol


Despite its poisonous properties, it has had several applications over the centuries. Currently, its extract is used in the manufacture of paclitaxol, a drug that slows the growth of ovarian, breast and lung cancer.
Symptoms: Eating the leaves and, to a lesser extent, the seeds cause dizziness, dry mouth, dilated pupils, weakness, irregular heartbeat and, possibly, death.
Location: United Kingdom
Toxins: toxic alkaloids such as taxine


It is cultivated for its seeds, from which castor oil is obtained, which in addition to being a powerful purgative is used in the manufacture of paints, varnishes, lubricants and brake fluids.
Symptoms: The seed coat is highly toxic, causing nausea, abdominal cramps, vomiting, internal bleeding and kidney failure.
Location: It is originally from Africa, but is currently distributed around the world.
Toxin: ricin


Belladonna poison affects the nervous system. In sufficient doses, it paralyzes the nerve endings of the involuntary muscles of the body, such as the blood vessels, heart and gastrointestinal muscles.
Symptoms: dilated pupils, sensitivity to light, blurred vision, headache, confusion, and seizures.
Location: Native to Europe, North Africa, and West Asia, but also found in some parts of North America.
Toxin: contains atropine and scopolamine in its stems, leaves, berries, and roots. 10 to 20 berries is enough to kill an adult.


Its beautiful seeds are often used in jewelry and rosary making. However, when the coating breaks, it can become very dangerous. Its venom prevents protein synthesis, one of the most important tasks of the cell.
Symptoms: Inhaling causes difficulty breathing, fever, nausea and fluid in the lungs. If swallowed (and the seed lining breaks) it causes nausea and vomiting leading to dehydration and atrophy of the kidneys, liver, and spleen. Death usually occurs within three to four days.
Location: It is native to Indonesia, although it is found around the world in tropical and subtropical climates.
Toxin: abrine. Only 3mg of this substance (less than what a seed contains) is enough to kill an adult.


It is considered the most poisonous plant on the American continent. Those who survive hemlock poisoning experience long-term conditions such as amnesia.
Symptoms: violent and painful seizures, nausea, vomiting, muscle cramps, and tremors.
Location: Native North American
Toxin: contains cicutoxin, which is more concentrated in the roots.


Considered the most poisonous plant in the world. It is so powerful that even honey created from its nectar can kill a person.
Symptoms: diarrhea, vomiting, severe stomach pain, drowsiness, dizziness, irregular heartbeat, and often death.
Location: Originally from the Mediterranean, it is found in other parts of the world such as China, Argentina, the United States, Spain, and Australia.
Toxins: contains several that act on the heart, the most powerful being oleandrin.

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