Top 10 Deadliest Plants

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Plants are often admired for their beauty and used for their nutritional value, but some contain compounds that can be deadly to humans. From dumbcane to white snakeroot, many plants have evolved with toxic substances that interfere with human biology.

Dumbcane, for example, is a common houseplant with needle-like crystals of calcium oxalate that can cause blisters and swelling in the mouth and throat, making it difficult to breathe or speak. Meanwhile, white snakeroot contains tremetol, which can cause secondary poisoning in humans who drink the milk of animals that have ingested the plant.

Foxglove, a common murder-plant, contains digitoxin, which can be toxic to humans, leading to symptoms like nausea, vomiting, and diarrhea, as well as confusion, hallucinations, and an irregular heartbeat. Similarly, the Pong-pong tree’s seeds contain cerberin, which interferes with normal heart function and can cause stomach symptoms and changes to heart rhythm, often leading to death within a few hours.

Oleander, a shrub that contains the poisonous oleandrin, can cause nausea, vomiting, diarrhea, dizziness, disorientation, and blurred vision. These are just a few examples of the many poisonous plants that exist in the world.

Key Takeaways

  • Many plants contain toxic substances that can interfere with human biology.
  • Poisonous plants like dumbcane, foxglove, and Pong-pong can cause symptoms like nausea, vomiting, and changes to heart rhythm, and can even lead to death.
  • White snakeroot can cause secondary poisoning in humans who drink the milk of animals that have ingested the plant.


Dumbcane, a common houseplant, is known for its attractive appearance and hilarious name. However, it can cause severe injuries to humans if ingested. The plant contains tiny crystals of calcium oxalate, an acid that is a major component of kidney stones.

These crystals are shaped like needles that can easily penetrate the tissues in the digestive system or eyes, causing blisters and swelling in the mouth and throat. The swelling can make it difficult to breathe or speak, hence the name. The sap of dumbcane can also cause similar damage if it comes into contact with sensitive areas like the eyes.

Botanists believe that the needles may contain enzymes that interfere with the proteins in the cells, making the swelling and burning worse. The effects of dumbcane poisoning can last for up to two weeks and can be fatal if the airway gets blocked. However, fatalities from dumbcane poisoning are relatively rare.

It is easy to grow and nice to look at, but it is important to stay away from dumbcane and avoid ingesting any part of the plant.


Foxglove, also known as digitalis, is a common plant that can be found in many gardens and landscapes. However, it is also known as a “murder-plant” due to its toxic properties. The plant contains digitoxin, a compound that is toxic to humans in larger doses. In smaller doses, digitoxin can be used as a heart medication.

Consuming foxglove can lead to symptoms such as nausea, vomiting, diarrhea, confusion, hallucinations, and an irregular heartbeat. It can also affect vision, causing things to appear blurry and yellowish. Van Gogh may have experienced these symptoms during his “Yellow Period” due to the medication he was given containing digitoxin.

Fatal cases of foxglove poisoning are rare, as most people do not consume large amounts of the plant. However, it is important to be aware of its toxic properties and to avoid ingesting it.


The Pong-pong tree is a plant native to Southeast Asia and some Pacific islands that can grow up to ten meters tall. Despite its unassuming appearance, just one seed from this tree is enough to cause death.

The seeds of the Pong-pong contain cerberin, a toxic substance similar to digitoxin, which interferes with normal heart function. It is not easy to ingest the seeds by accident since they have to be removed from a harder husk first. However, people who end up with cerberin poisoning experience stomach symptoms and changes to their heart rhythm, and often die within a few hours.

It is important to note that fatal cases of Pong-pong poisoning are rare, but the effects can be severe and potentially life-threatening. Therefore, it is recommended to stay away from this tree and its seeds altogether.


Oleander is a highly toxic plant that contains several poisonous compounds, with oleandrin being the most dangerous one. The plant is native to the Mediterranean region and is commonly found in warm climates around the world.

Ingesting any part of the oleander plant, including its flowers, leaves, and stems, can cause a range of symptoms, including nausea, vomiting, diarrhea, dizziness, disorientation, and blurred vision. The plant’s toxic compounds interfere with the heart’s beating, which can eventually be fatal, although it usually isn’t.

Interestingly, Pliny the Elder wrote about oleander way back in the year 77 CE, describing it as deadly to livestock but a cure for snakebites. However, oleander doesn’t work as an antidote to snake venom, and eating it would probably just speed up the whole dying process.

In conclusion, it’s best to stay away from oleander and avoid ingesting any part of the plant, as it can be extremely harmful to human health.


Aconite, also known as monkshood or wolfsbane, is a highly poisonous plant that contains a complicated-looking compound called aconitine. This compound interferes with the human heart and brain, causing a range of severe symptoms. People who ingest aconite, especially the roots or tubers, can experience muscle weakness, tingling, numbness, irregular heartbeat, low blood pressure, nausea, vomiting, and diarrhea.

Aconite poisoning has been mentioned as a cause of death in ancient writings, and even today, about 6% of people who are hospitalized with aconite poisoning die. The plant is also known for its use in traditional medicine, where it was used as a painkiller and sedative. However, due to its high toxicity, aconite is not recommended for medicinal use.

It is important to note that aconite is not to be confused with other plants that share similar names, such as marshmallow, which is a common ingredient in herbal teas and cough medicines. It is crucial to properly identify any plant before ingesting it, as many plants can be highly toxic and even deadly.


Hemlock is a poisonous plant that has been made famous by ancient writings, including accounts of Socrates’ execution, as he was forced to drink a hemlock-based poison. Hemlock can look a lot like the wild parsnip, celery, and carrot plants, which can lead to accidental poisoning.

The plant contains a few different compounds that make it especially dangerous, but the worst of them is probably coniine. Coniine interferes with the signals between neurons, causing dizziness and trembling, slowing down the heart rate, and eventually causing paralysis.

It can be fatal because the diaphragm, the muscle that helps control breathing, also becomes paralyzed. However, if a modern patient can get on a ventilator to help them breathe until the poison wears off, they’ll be okay.

Hemlock is not the only plant on this list that can cause fatal poisoning. Plants like dumbcane, foxglove, Pong-pong, oleander, aconite, deadly nightshade, and rosary pea contain toxic compounds that can lead to severe symptoms like nausea, vomiting, diarrhea, and even death. It is essential to stay away from these plants, no matter how pretty or delicious they may seem.

Deadly Nightshade

Deadly nightshade is a highly poisonous plant that can be deadly if ingested. The plant contains atropine and solanine, which are toxic chemicals that can cause a wide range of symptoms. Eating just 10 to 20 berries of the plant can be enough to kill an adult. The berries of the deadly nightshade plant are often mistaken for blueberries, making it easy to accidentally ingest the poisonous fruit.

The symptoms of deadly nightshade poisoning are numerous and can affect practically every part of the body. These symptoms include nausea, vomiting, diarrhea, muscle weakness, tingling, numbness, irregular heartbeat, low blood pressure, dizziness, disorientation, blurred vision, and even death.

It is possible to build up a tolerance to the toxins in deadly nightshade, but this is not recommended as the risks of poisoning are too great. In fact, history is full of stories of assassins who used their own tolerance to the poison to trick their victims into ingesting it.

Overall, deadly nightshade is a plant that should be avoided at all costs. The risks of poisoning are too great, and the symptoms can be severe and potentially fatal.

Rosary Pea

The rosary pea is a bright red berry found on a bush that contains one of the most poisonous substances in the world. It is called abrin, which is a ribosome-inactivating protein that stops the ribosomes in a cell from functioning. This protein is so potent that just one tenth of a milligram can kill an adult. The symptoms usually start with gastrointestinal problems such as nausea, vomiting, and diarrhea. Eventually, the victim experiences internal bleeding and organ damage, leading to death in almost all cases. There is no antidote for abrin, making it an extremely dangerous poison.

It is important to note that the information presented in this section is not intended to be exhaustive, and there are many other poisonous plants that can be harmful to humans. It is always best to exercise caution and avoid consuming any plant or berry unless it has been verified as safe for consumption.

White Snakeroot

White snakeroot is a poisonous plant that contains tremetol, a mix of compounds that can be deadly to humans and animals. The plant is known to cause a condition called milk sickness, which occurs when animals ingest the plant and their milk becomes contaminated with tremetol. People who consume the contaminated milk can experience symptoms such as vomiting, tremors, and weakness, and the condition can be fatal.

White snakeroot is found in North America and is often found in wooded areas and along streams. The plant can grow up to five feet tall and has clusters of small white flowers. The leaves of the plant are pointed and serrated, and the stems are hairy.

To avoid the dangers of white snakeroot, it is important to be able to identify the plant and to avoid consuming any milk or meat from animals that may have ingested it. Symptoms of milk sickness can appear within hours of consuming contaminated milk or meat, and can progress quickly if left untreated. If you suspect that you or someone you know may have ingested white snakeroot, seek medical attention immediately.