What is the Most Poisonous Plants to Humans?

shutterstock 1414558430 FloraQueen EN What is the Most Poisonous Plants to Humans?

Many of the plants you have in your yard, garden, and home look pretty, but they can also be quite dangerous. It is important to arm yourself with information about poisonous plants to humans so that you don’t risk your health and that of your children and friends.

In this article, you are going to learn about:

Deadly Nightshade
• Castor Bean
• White Snakeroot
• Tobacco Plant
• Rosary Pea
• Water Hemlock
• Oleander

Deadly Nightshade

The legend surrounding Deadly Nightshade is that Macbeth’s soldiers added it to the wine they gave to the Danes to poison them. In reality, though, children often fall victim to this devilish plant because the berries are quite sweet. Even some adults don’t notice what they’re eating and consume the lethal plant.

It’s primarily found in southern and central Eurasia in waste and wooded areas. You can easily see the green leaves are dull, and the berries are black and shiny, often the size of a cherry. The leaves, stems, roots, and berries all contain scopolamine and atropine. These things can cause paralysis of all involuntary muscles of your body, which includes the heart. Those with severe skin sensitivity may find their skin is irritated if they come in contact with any part of the plant.

Castor Bean

Castor bean is often grown as an ornamental and is commonly found in Africa. It’s a highly attractive plant and is used for many purposes. For example, the seeds can be taken from the plant, processed, and turned into castor oil. However, the seeds also contain ricin, which is a poison that can be deadly in very small quantities. In fact, it takes just a couple of seeds to kill children and eight seeds to kill adults.

Ricin makes it harder for the cells to synthesize proteins. Often, symptoms include diarrhea, severe vomiting, seizures, and death.

The poison killed Georgi Markov in 1978. He was a journalist who often spoke against the Bulgarian government. It’s also been mailed to many politicians in the US in terrorism attempts. Generally, accidental ingestion by pets and children are where most of the fatalities occur.

White Snakeroot

White snakeroot is another deadly plant, and it actually killed Nancy Hanks, Abraham Lincoln’s mother. It looks quite pretty and harmless with its tiny white clusters of flowers and long, stalk-like stems. Still, it contains trematol, a toxic alcohol.

Of course, it is deadly if you directly ingest any part of the plant. However, Lincoln’s mother drank milk from a cow that had eaten from the plant. Today, it is still true that milk and meat from animals who ate the plant can contain the toxin and pass it to consumers.

Symptoms of eating this plant or tainted meat and milk from animals who ate it can include nausea, loss of appetite, abdominal discomfort, weakness, more acidity in the blood, a red tongue, and death.

Farmers now know about this issue and make sure to remove it from animal pastures to prevent their animals from eating it.

Tobacco Plant

Tobacco is a commercialized plant that is not used for food. It’s highly popular as cigarettes, which are highly addicting. Every part of the plant contains anabasine and nicotine alkaloids, and they are both highly toxic. Still, the leaves are where most of the toxins stay.

Despite the fact that it is a cardiac poison, tobacco plants, and especially the nicotine within them, are widely consumed throughout the world. It’s addictive and psychoactive. Usage of tobacco in any form causes over 5 million deaths each year. Some scientists say that it is one of the most poisonous plants to humans.

Rosary Pea

Rosary peas are sometimes called jequirity beans. The seeds contain a deadly protein called abrin, which inhibits ribosome creation. They’re native to many tropical areas of the world and are used in prayer rosaries and jewelry, hence the name.

The good news is that the seeds aren’t poisonous if they’re whole. However, if they are broken, scratched, or chewed up, they can be deadly. Just three micrograms of the deadly abrin are enough to kill an adult. Generally, there is more than that in a single seed.

Many jewelry makers have died or become extremely ill after pricking fingers while using the seeds. Organ failure can occur in just four days. Quick action and a hospital visit can help, but it is not often possible to realize that you have been poisoned by the rosary pea in time.

Water Hemlock

Water hemlock is related to the poison hemlock plant, which killed Socrates. It’s been called the most toxic plant in all of North America. Many people like the look of it because it is similar to Queen Anne ’s lace. Often, it is confused with celery or parsnips. That’s mainly because it’s part of the carrot family but a wildflower or weed.

However, this plant has cicutoxin in it, especially within the roots. If you happen to eat it, you are going to get very sick. Convulsions, nausea, and abdominal cramps are just some of the issues you could face. Plus, death is also a possibility. Those who survive eating this toxic plant usually have lasting tremors and amnesia.


One of the prettiest plants in all the world, Oleander, is also highly lethal. In Ancient Rome, it was described as a beautiful plant with striking flowers. With that, it is commonly grown as an ornamental and hedge. Still, every part of the plant is deadly and contains nerine and oleandrin, both of which are cardiac glycosides.

If you eat any part of the plant, you can experience an erratic pulse, diarrhea, vomiting, coma, seizures, and death. Even if you just make contact with the leaves or get sap on you, it can be highly irritating to the skin in some people with sensitivities. This makes it one of the most poisonous plants to humans.

In fact, the toxins within the oleander plant are so potent that some people have gotten ill after consuming honey from bees that pollinated those flowers! While fatalities from the plant are quite rare, you never know. Of course, the plant tastes bitter, but if you eat it on accident, you could be in for a bad night.

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