23 Deadly Plants to NEVER Touch: Linked to Over 21,400 Poisoning Cases

Did you know that in 2021, plants were the culprits in over 21,400 poisoning cases ¹, making up 3.6% of all reported poison exposures? As a nature enthusiast, I’m always drawn to the stunning diversity of the plant world—from the bright blossoms to the verdant leaves.

Yet, beauty in nature can sometimes be deceiving. Some plants, as lovely as they are, carry hidden dangers that can be seriously harmful or even fatal upon contact or ingestion.

Here are 23 poisonous plants that, while not all lethal, are best avoided to ensure your safety—this guide separates surprising truths from common myths.

1. Rosary Pea

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The rosary pea, with its vibrant red and black seeds, may look like a tempting addition to your jewelry collection. However, these seeds contain a highly toxic substance called abrin, which can be fatal if ingested. In fact, just one seed is enough to kill an adult human ².

Interestingly, the rosary pea has been used in various cultures for centuries, from being used as beads in jewelry to being used in traditional medicine. However, the risks far outweigh any potential benefits, and it’s best to admire this plant from a safe distance.

2. Castor Bean

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The castor bean plant, which is commonly used to make castor oil, is another plant that should be avoided at all costs. The seeds of this plant contain ricin, a highly toxic substance that can cause severe illness or death if ingested.

What’s even more alarming is that the castor bean plant is incredibly common, and can be found in many gardens and public spaces. In fact, the plant is so dangerous that it has even been used as a biological weapon in the past.

3. Oleander

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Oleander is a beautiful flowering shrub that is commonly found in gardens and public spaces. However, every part of this plant, from the leaves to the flowers, is highly toxic if ingested. In fact, just one leaf can be fatal ³.

Despite its toxicity, oleander has been used in traditional medicine for centuries, and is even being studied for its potential anti-cancer properties. However, the risks of ingesting this plant far outweigh any potential benefits, and it’s best to admire its beauty from a safe distance.

4. Poison Sumac

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Poison sumac is a plant that is commonly found in swampy areas of the eastern United States. Like its relatives, poison ivy and poison oak, poison sumac contains an oil called urushiol that can cause a severe allergic reaction if touched.

What’s even more alarming is that the allergic reaction caused by poison sumac can be much more severe than that caused by poison ivy or poison oak. In fact, some people have even been hospitalized after coming into contact with this plant.

5. Tobacco

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Tobacco is a plant that is commonly used in cigarettes and other smoking products. However, what many people don’t realize is that tobacco is actually highly toxic, and can cause severe illness or death if ingested in large quantities.

In fact, tobacco contains a substance called nicotine, which is highly addictive and can cause a range of health problems, from lung cancer to heart disease. Despite the well-known risks associated with smoking, tobacco remains one of the most widely used plants in the world.

6. Jimson Weed

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Jimson weed is a plant that is commonly found in fields and along roadsides in the United States. However, every part of this plant, from the leaves to the seeds, is highly toxic if ingested. In fact, just a small amount of jimson weed can cause severe hallucinations, delirium, and even death .

Despite its toxicity, jimson weed has been used in traditional medicine for centuries, and is even being studied for its potential medicinal properties. However, the risks of ingesting this plant far outweigh any potential benefits, and it’s best to avoid it altogether.

7. Poison Oak

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Poison oak is another plant that contains the toxic oil urushiol, which can cause a severe allergic reaction if touched. Like poison ivy, poison oak is commonly found in wooded areas throughout the United States.

What’s even more concerning is that the allergic reaction caused by poison oak can be much more severe than that caused by poison ivy. In fact, some people have even developed a systemic allergic reaction after coming into contact with this plant.

8. Manchineel Tree

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The manchineel tree is a plant that is commonly found in the Caribbean and Central America. However, every part of this tree, from the leaves to the fruit, is highly toxic if ingested or touched. In fact, even standing under the tree during a rainstorm can cause severe blistering and irritation.

Despite its toxicity, the manchineel tree has been used in traditional medicine for centuries, and is even being studied for its potential anti-cancer properties. However, the risks of coming into contact with this tree far outweigh any potential benefits, and it’s best to avoid it altogether.

9. Deadly Nightshade

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Deadly nightshade is a plant that is commonly found in Europe and Asia. However, every part of this plant, from the leaves to the berries, is highly toxic if ingested. In fact, just a few berries can cause severe illness or death.

Despite its toxicity, deadly nightshade has been used in traditional medicine for centuries, and is even being studied for its potential medicinal properties. However, the risks of ingesting this plant far outweigh any potential benefits, and it’s best to avoid it altogether.

10. Hogweed

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Hogweed is a plant that is commonly found in Europe and Asia. However, the sap of this plant contains a substance called furocoumarin, which can cause severe blistering and irritation if touched.

What’s even more concerning is that the blistering caused by hogweed can be so severe that it can leave permanent scars. In fact, some people have even required hospitalization after coming into contact with this plant.

11. White Snakeroot

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White snakeroot is a plant that is commonly found in the eastern United States. However, this plant contains a toxic substance called tremetol, which can cause severe illness or death if ingested.

Interestingly, white snakeroot was actually responsible for the death of Abraham Lincoln’s mother, Nancy Hanks Lincoln, who died of “milk sickness” after consuming milk from a cow that had eaten the plant.

12. Stinging Nettle

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Stinging nettle is a plant that is commonly found in Europe and North America. However, the leaves and stems of this plant are covered in tiny hairs that contain formic acid, which can cause a painful and irritating rash if touched.

Despite its painful sting, stinging nettle has actually been used for centuries in traditional medicine, and is even being studied for its potential health benefits. However, it’s best to avoid touching this plant without proper protection.

13. Dumb Cane

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Dumb cane is a popular houseplant that is commonly found in homes and offices. However, every part of this plant, from the leaves to the stem, contains calcium oxalate crystals that can cause severe irritation and swelling if ingested or touched.

In fact, the name “dumb cane” actually comes from the fact that ingesting the plant can cause the tongue and throat to swell, making it difficult to speak.

14. Larkspur

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Larkspur is a beautiful flowering plant that is commonly found in gardens and public spaces. However, every part of this plant, from the leaves to the seeds, is highly toxic if ingested. In fact, just a small amount of larkspur can cause severe illness or death.

Despite its toxicity, larkspur has been used in traditional medicine for centuries, and is even being studied for its potential medicinal properties. However, the risks of ingesting this plant far outweigh any potential benefits, and it’s best to admire its beauty from a safe distance.

15. Castor Oil Plant

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The castor oil plant, which is commonly used to make castor oil, is another plant that should be avoided at all costs. Like the castor bean plant, the seeds of the castor oil plant contain ricin, a highly toxic substance that can cause severe illness or death if ingested.

What’s even more concerning is that the castor oil plant is incredibly common, and can be found in many gardens and public spaces. In fact, the plant is so dangerous that it has even been used as a biological weapon in the past.

16. Angel’s Trumpet

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Angel’s trumpet is a beautiful flowering plant that is commonly found in gardens and public spaces. However, every part of this plant, from the leaves to the flowers, contains toxic alkaloids that can cause severe illness or death if ingested.

Despite its toxicity, angel’s trumpet has been used in traditional medicine for centuries, and is even being studied for its potential medicinal properties. However, the risks of ingesting this plant far outweigh any potential benefits, and it’s best to admire its beauty from a safe distance.

17. Moonseed

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Moonseed is a plant that is commonly found in the eastern United States. However, the berries of this plant contain a toxic substance called dauricine, which can cause severe illness or death if ingested.

What’s even more concerning is that the berries of the moonseed plant look very similar to grapes, which can lead to accidental ingestion. In fact, there have been several reported cases of children being poisoned after eating moonseed berries.

18. Water Hemlock

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Water hemlock is a plant that is commonly found in wetland areas throughout North America. However, every part of this plant, from the leaves to the roots, contains a toxic substance called cicutoxin , which can cause severe illness or death if ingested.

In fact, water hemlock is considered to be one of the most toxic plants in North America, and has been responsible for the deaths of both humans and animals.

19. Death Camas

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Death camas is a plant that is commonly found in western North America. However, every part of this plant, from the leaves to the bulbs, contains toxic alkaloids that can cause severe illness or death if ingested.

What’s even more concerning is that the bulbs of the death camas plant look very similar to edible onions, which can lead to accidental ingestion. In fact, there have been several reported cases of people being poisoned after eating death camas bulbs.

20. Poison Hemlock

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Poison hemlock is a plant that is commonly found in Europe and North America. However, every part of this plant, from the leaves to the seeds, contains toxic alkaloids that can cause severe illness or death if ingested.

In fact, poison hemlock is so toxic that it was actually used to execute the ancient Greek philosopher Socrates, who was sentenced to death by drinking a cup of poison hemlock.

21. Poison Ivy

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Poison ivy is a plant that is commonly found in wooded areas throughout North America. However, every part of this plant, from the leaves to the stem, contains an oil called urushiol that can cause a severe allergic reaction if touched.

What’s even more concerning is that the allergic reaction caused by poison ivy can be incredibly painful and long-lasting, with symptoms including severe itching, blistering, and swelling.

22. Giant Hogweed

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Giant hogweed is a plant that is commonly found in Europe and Asia. However, the sap of this plant contains a substance called furocoumarin, which can cause severe blistering and irritation if touched.

What’s even more concerning is that the blistering caused by giant hogweed can be so severe that it can leave permanent scars. In fact, some people have even required hospitalization after coming into contact with this plant.

23. Gympie Gympie

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The gympie gympie tree is a plant that is commonly found in Australia (also known as Suicide plant). However, every part of this tree, from the leaves to the fruit, is covered in tiny hairs that contain a toxic substance called moroidin, which can cause severe pain and irritation if touched.

In fact, the pain caused by the gympie gympie tree is so severe that it has been described as being worse than childbirth or a gunshot wound. Some people have even reported feeling the effects of the toxin for months or even years after coming into contact with the plant .

Stay Safe & Healthy

While plants are an essential part of our ecosystem and provide us with countless benefits, it’s important to be aware of the potential dangers that some plants can pose.

By educating ourselves about these dangerous plants and taking the necessary precautions to avoid them, we can continue to enjoy the beauty and wonder of the natural world while staying safe and healthy.

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Davin is a jack-of-all-trades but has professional training and experience in various home and garden subjects. He leans on other experts when needed and edits and fact-checks all articles.