Top 10 Poisonous Plants in The World

Humans and animals have been dependent to plant from the very beginning of the life on Earth. A significant amount of the molecular oxygen in the world is produced by green plants and most of Earth’s ecosystems get their energy from the sugars produced by green plants. Plants have been directly consumed as food source by humans and animals. Animals either consume plants directly or depend on other life forms that do so. Herbivores (plant eating animals) are important players in the food chain because they eat plants to get carbohydrates that plants create through photosynthetic processes. And as a part of food chain they are eaten by carnivorous animals. Basically plants makes life on earth possible.

top 10 most poisonous plants in the world

We have been domesticating grains, fruits, and vegetables for millennia because they are necessary for our survival. Humans use plants for a wide range of things, including construction materials, furnishings, writing materials, and a wide variety of medicinal uses. Approximately 3,82,000 plant species have now been documented by humans. Roughly 2,83,000 of them, or the majority, produce seeds. Some of these plants produces fruits, some are huge and provides shelters for birds and animals. And some are poisonous, that are capable of taking life’s. So, in this article we are going to visit a scary world of plants.

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Top 10 Poisonous Plants in The World

There was a time when peoples used to believe in the legends of man eating plants. Although in the modern time all those myth are busted; however we know about the poisonous plants that are capable of producing toxins enough to neutralize an adult. Let’s climb into the list of top 10 poisonous plants in the world.

10. Aconite (Wolfsbane)

wolfsbane
aconite
wolfsbane (aconite) [Image source: https://sites.evergreen.edu/]

Aconitum is a genus of about 250 species of floral plants within the Ranunculaceae family, more commonly known by the names aconite, monkshood, or wolfsbane. These herbaceous perennials flourish best in the well-draining, moisture-retaining soils of mountain meadows and are largely native to the mountainous regions of North America, Europe, and Asia in the Northern Hemisphere. This plant’s leaves are spherical and separated palmately into 5-7 well-lobed segments. It has purple helmet-shaped flowers, which is why it is also known as monkshood. It can grow to be 1 meter (3 feet) tall.

Aconite is found throughout history. It is believed to be one of the first poisons created in Greece, which was used to poison rivals in Rome. Wolfsbane got its name because its poison was used in the 18th century to kill predators like wolves and panthers. The poison was injected into raw flesh to lure the animals. Because of its horrible side effects, some people even thought that aconite was the reason these animals later developed rabies.

Its seeds and roots have the highest concentration of aconitine. When ingested, it acts by opening sodium channels that are already responsive to tetrodotoxins. This results in a rise in sodium flow through the blood vessels and delays in repolarization, making the person more prone to heart failure. The poison causes severe nerve paralysis, lowers blood pressure, and eventually causes the heart to stop. This poisoning is the result of taking too much aconite. Wearing gloves is advised when gardening with A. napallus since touching the flowers might prove risky.

9. Ageratina Altissima (White Snakeroot)

White snakeroot
White snakeroot [Image source: https://www.gardeningknowhow.com/]

A poisonous perennial herb in the Asteraceae family, Ageratina altissima is native to eastern and central North America and known by many different names, including richweed, white sanicle, and white snakeroot. Usually found in woodlands and meadows, snakeroot reaches a height of two to four feet and grows mostly in moist, partially shaded areas. It can self seed and spread quickly in the surrounding area through fibrous rhizomes. White snakeroot plants have coarsely shaped, round-based leaves with pointy points that grow in opposing directions on erect stems. The branches split at the top, where white flower bunches blossom from summer through the winter.

Tremetol, (the toxin found in white snakeroot), contaminates cattle’s milk and flesh when its leaves are consumed by livestock’s. Humans can become infected with the poison by drinking toxin-containing milk or meat. It can result in tremetol poisoning in humans if ingested in large amounts. The illness is also known as “milk sickness” since the toxin was frequently consumed by humans through the milk of cows that had consumed snakeroot. Milk sickness claimed thousands of lives in the Midwest and Upper South during the early 19th century when a big influx of European Americans from the East arrived to settle in the white snakeroot’s natural habitat.

8. English Yew (Taxus baccata)

English yew
English yew [Image source: https://ipm.missouri.edu/]

Native to Northwest Africa, northern Iran, Southwest Asia, and Western and Central Europe, Taxus baccata is a species of evergreen tree in the Taxaceae family. These tree can grow upto 20 meters high. It has a straight needle like pointed leaves which is green in upper part and greenish-gray in lower part. They grow in two rows in either side of each twig. As yew trees are dioecious, it’s male and female flowers grow on different trees. These can be observed on April and March. Male flowers are little, globe-shaped, white-yellow structures. While young, female flowers are green and bud-like, but as they age, they turn brown and resemble acorns.

The common yew, unlike many other conifers, does not produce seeds in cones. Instead, each seed is protected by a red, fleshy, berry-like structure known as an aril, which is open at the tip. Both small mammals like squirrels and dormice as well as birds like the blackbird, mistle thrush, song thrush, and fieldfare consume the fruit. The caterpillars of the satin beauty moth enjoy the leaves.

Yew trees contain very toxic taxane alkaloids, which have been developed as anti-cancer medications. Eating just a few leaves can make a small kid seriously ill, and a few deaths have been reported associated with yew poisoning. Every part of the tree is poisonous. Yew poisonings are extremely prevalent in both domestic and wild animals that ingest the plant accidently, causing numerous deaths of livestock.

7. Cerbera Odollam (Pong Pong)

Cerbera Odollam (Pong Pong)
Pong Pong [Image source: https://sites.evergreen.edu/]

Cerbera odollam is a plant species from the Apocynaceae family. It is often referred to as the ‘suicide tree’ because of its powerful cardiotoxic effects, which make it a suitable ways of attempting suicide. The plant thrives in damp areas of South India, Madagascar, and Southeast Asia, and its common names are Pong-Pong and Othalanga. It grows to a height of roughly 10-12 meters. Their leaves are glossy, and the flowers are white with yellow throats. The plant as a whole produces milky, white latex.

It grows mango-like fruit, which is 5 to 10 centimeters long, is green at first and turns reddish as it matures. Its oval kernel, which is about 2 cm by 1.5 cm and contains two extremely lethal seeds, is encased in a green fibrous shell. The white kernel turns violet, then dark grey, and finally brown or black when it comes into contact with air. The toxic substance found in Cerbera odollam kernels, cerberin, is a cardiac glycoside and blocks the heart’s sodium and potassium ATPase. A lethal amount of the poison can be found in a single kernel.

During the 18th and 19th centuries, consumption of Cerbera odollam seeds caused approximately 3,000 deaths annually in Madagascar following a trial by ordeal. The purpose of these trials was to establish the subject’s guilt or innocence of a crime, usually witchcraft. Cerbera odollam was also widely used for suicide and is still used for this reason today. Because of their toxicity, Cerbera odollam seeds are used as biopesticides, insect repellents, and rat poisons.

6. Brugmansia (Angel’s Trumpets)

Brugmansia (Angel's Trumpets)
Angel’s Trumpet [Image source: https://www.strangewonderfulthings.com]

Brugmansia is a genus comprising seven flowering plant species from the nightshade family Solanaceae. They are woody shrubs or trees with pendulous blooms and fruit without spines. Their huge, fragrant flowers are what give them the popular name “angel’s trumpets,” which is adopted from the term “devil’s trumpets” associated with the closely related genus Datura. Brugmansia was previously classified as a subgenus of Datura, but it is now recognized as a separate genus. The two of them are easily distinguishable. Datura flowers face upward, while Brugmansia flowers are pendulous.

They can grow as high as 11 meters. The leaves are alternately distributed along the stems and are normally big, measuring 10-30 cm (4-12 in) long and 4-18 cm (2-7 in) wide. They have a complete or coarsely toothed border and are frequently covered in fine hair. they bear huge, pendulous, trumpet-shaped flowers that are 14-50 cm (6-20 in) long and 10-35 cm (4-14 in) wide at the opening. Their flowers have various shades of white, yellow, pink, orange, green, and red. mostly have a strong, pleasant fragrance that is especially noticeable in the evening. Flowers might be single, double, or more.

Brugmansia is native to tropical regions of South America, including the Andes from Venezuela to northern Chile, as well as south-eastern Brazil, and is grown as an attractive plant all over the world. Every part of Brugmansia are potentially toxic, but the seeds and leaves are particularly deadly. Brugmansia contains high levels of scopolamine (hyoscine), hyoscyamine, and other tropane alkaloids that can cause anticholinergic toxidrome and delirium. Ingestion can cause smooth muscle paralysis, confusion, tachycardia, dry mouth, constipation, tremors, migraine headaches, poor coordination, delusions, visual and auditory hallucinations, mydriasis, acute cycloplegia, and death.

5. Nerium Oleander (Rosebay)

Oleander
Oleander [Image source: https://plantsexpress.com/]

Nerium oleander, commonly referred to as rosebay or oleander, is a small tree or shrub that is used as an ornamental and landscaping plant throughout temperate and subtropical regions of the world. It can reach heights of 6.5 feet to 19.5 feet and widths of 6 feet to 10 feet. It is the perfect option for the use as a screening plant due to the size of it. This plant has a range of floral hues and blooms from late spring to late summer. Breaking branches release a thick sap that can lead to contact dermatitis.

The toxic chemicals found in oleander have historically led to its classification as a lethal plant, especially when ingested in high quantities. These substances include the cardiac glycosides oleandrin and oleandrigenin, that have a limited therapeutic range and are toxic when consumed. But because of its bitterness, which makes it inedible to most animals and people, poisoning incidents are rare and the overall risk of human death is minimal. Greater doses may result in dyspepsia, excessive salivation, nausea, vomiting, diarrhea, and irregular heartbeat. Prolonged sap exposure can lead to dermatitis, eye inflammation, as well as skin irritation.

4. Manchineel (Little Apple of Death)

Manchineel
Manchineel [Image source: https://www.treehugger.com/]

In their natural environments, which include the sandy soils and mangroves of South Florida, the Caribbean, Central America, and northern South America, manchineels are notorious. Warning signs are tied onto these trees. The manchineel trees can grow upto the height of 15 meters (49 ft.). It has shiny green leaves, small greenish-yellow flowers, and reddish-grayish bark. The leaves measure 5 to 10 centimeters (2 to 4 inches) in length, they are simple, alternating, and feature extremely tiny serrations or teeth. Little green flowers grow in spikes, and when ripe, the fruits resemble apples and are either green or greenish-yellow. Like all the other parts of the tree, its fruit is also poisonous.

Strong poisons are present in all parts of the manchineel. Phenol along with other skin irritants are found in its milky white sap, which can cause severe allergic contact dermatitis. Even standing under a tree in the rain can blister your skin just by coming into contact with the liquid; even a small droplet carrying sap will do this. If the smoke from burning a tree gets in your eyes, it could hurt them as well.ย Its milky sap, or latex, can cause extensive corneal epithelial defects, acute keratoconjunctivitis, and bullous dermatitis when it comes into contact with the skin.

3. Cicuta (Water Hemlock)

image 91
Water hemlock [Image source: https://learnyourland.com/]

Cicuta, also known as water hemlock, is a genus of four very poisonous plants in the family Apiaceae. Due to its extreme toxicity to humans, water hemlock is widely regarded as North America’s most poisonous plant. It is closely linked to the poison hemlock plant which was notoriously used to kill Socrates. These are tall, perennial herbaceous plants that can reach a height of 2.5 meters (8 feet). Cicuta spp. are biennial plants that have identical structure. They are distinguished by their small, umbrella-shaped (umbel-shaped) green or white flowers. Except for splits at the point where the leaves meet the stem, the plant’s stem is branched, upright, smooth, and hollow; on occasion, it has purple stripes.

The plant blooms in the spring or early summer; the flowers are small, with green or white petals got together in an umbrella form (umbel) unique to this family. The plant spreads predominantly through seeds, which are produced in large numbers and are small in size.

Cicutoxin, a toxin found in water hemlock, is known to cause seizures in those who ingest it. Although the toxin is present throughout the entire plant, it has its greatest concentration in the roots, especially during the spring. Additional symptoms involve dizziness, shaking, nausea, vomiting, and stomach aches. The main reason of death often involves respiratory failure or ventricular fibrillation, which can occur within hours of intake. Numerous people have died as a result of consuming the plant in the 20th and 21st centuries.

2. Ricinus (Castor Oil Plant)

Ricinus
Ricinus [Image source: https://www.gardenia.net/]

Ricinus communis, also known as castor bean or castor oil plant, is a perennial flowering plant in the spurge family Euphorbiaceae. They are native to India, Eastern Africa, and the Mediterranean basin. This shrub grows quickly, sprouting up suckers, and can get as big as a small tree, reaching a height of around 12 meters (39 ft.). It has a wide range of growth habits and appearances. Breeders have expanded the variability by choosing a variety of hybrids for leaf and flower color, as well as oil production. ]

The shiny leaves have coarsely serrated segments and are between 15 and 45 centimeters (6 and 18 inches) in length. They are alternating, palmate, and have five to twelve shallow lobes. In some varieties, they start as a dark reddish purple or bronze while they are young and progressively turn a dark green as they get older, occasionally with an undertone of reddish purple. The fruit is a spiny, greenish (to reddish-purple) capsule that contains big, glossy, round, highly toxic seeds that resemble beans and have different brownish mottling.

The plant’s seeds are used to make castor oil, but the seeds also contain ricin, a very harmful toxin that is stronger than the venoms of many snakes, strychnine, and cyanide. Actually, single seed will cause you to die slowly and agonizingly over the course of two days, suffering from a terrible stomach ache accompanied by bloody diarrhea and vomiting. Ricine is approximately 6000 times more toxic than cyanide. Given that it requires one castor oil seed to kill a fully grown human, eleven to kill a dog, and an enormous amount of eighty to kill a duck, humans are the ones that are most susceptible to these seeds.

1. Abrus Precatorius (Rosary Pea)

Rosary pea
Rosary pea [Image source: https://thesurvivalgardener.com/]

Abrus precatorius, commonly recognized as jequirity bean or rosary pea, is a herbaceous flowering plant from the bean family Fabaceae. The plant is widespread to Asia and Australia. It is a thin, perennial climber with long, pinnate-leafed leaves that twines around trees, shrubs, and hedges. is a strongly invasive plant in warm temperate to tropical climates, with a spread that is now virtually pantropical. It had been widely introduced by humans, and birds transported the vividly colored, hard-shelled seeds.

The seeds are the most lethal part and, oddly enough, due of their attractive orange-red color with a single black spot, these are frequently used as jewelry beads. Though the seeds have a strong outer shell that allows them to pass through the human digestive system, they contain abrin, a poison that is approximately 75 times stronger than ricin. Even when the seeds are utilized as bracelet or necklace beads, they present a significant risk, as jewelry makers have died from pricking their fingers on the drill bits used to create the tiny holes in the seeds.

Therefore, if the seed is bitten or scraped, it may be the most deadly plant on the planet, able to kill an adult with just three micrograms.

Conclusion

There are other different plants which are poisonous and this list was based on the potential of toxin to kill adult humans. So, don’t get confused by long lists of plants and be aware of the danger these plants posses to your life.

Also Donโ€™t Forget to Check the list of

Top 10 Poisonous Snakes in The World

Top 10 Largest Snakes in The World

Video Reference

Other References

  • https://sites.evergreen.edu/plantchemeco/wolfsbane-fictious-plant-contains-very-real-dangers/
  • https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/yew/
  • https://www.inaturalist.org/taxa/343758-Cerbera-odollam
  • https://plants.ces.ncsu.edu/plants/brugmansia/#poison
  • https://plants.ces.ncsu.edu/plants/nerium-oleander/
  • https://www.fs.usda.gov/wildflowers/plant-of-the-week/cicuta_maculata.shtml
  • https://science.howstuffworks.com/life/botany/the-12-deadliest-plants-in-the-world.htm

About Author

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Jyoti Bashyal

Jyoti Bashyal, a graduate of the Central Department of Chemistry, is an avid explorer of the molecular realm. Fueled by her fascination with chemical reactions and natural compounds, she navigates her field's complexities with precision and passion. Outside the lab, Jyoti is dedicated to making science accessible to all. She aspires to deepen audiences' understanding of the wonders of various scientific subjects and their impact on the world by sharing them with a wide range of readers through herย writing.

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