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Nerium oleander - Another stunning flower with the ability to cause serious harm. Ingested, a single leaf is a enough to kill a human. Hapless herbivores often succumb to its tasty but deadly petals.

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The crab’s eye -

The seeds of this plant contain deadly abrin, an extremely toxic toxalbumin. If chewed and ingested, one seed alone can be fatal.

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Round-leaved sundew -

A carnivorous plant that snacks on insects that are attracted to the glistening drops of sweet mucilage covering its leaves.

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Poison hemlock -

Highly poisonous, this plant enjoys a notorious past. Socrates's assassins were said to have used poison containing deadly coniine and pyridine-type alkaloids drawn from the plant, to murder the great philosopher.

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Dracula’s flower -

When in bloom, this sinister-sounding plant emits a very unpleasant odor—a warning in itself! The whole plant is toxic and touching it may result in skin irritation.

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Deadly nightshade -

The sweetness of its berries has led children and even adults to snack on this lethal plant, a mistake that can lead to frightening symptoms of paralysis.

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Water hemlock -

Also known as cicuta, anyone unfortunate enough to ingest any part of this highly toxic plant will suffer violent seizures, which may lead to death.

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Tobacco plant -

This is arguably the world's deadliest plant. Its leaves contain the toxic alkaloids nicotine and anabasine. Cigarettes really can harm your health.

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Manchineel tree - This is one of the most dangerous trees in the world, with every part of it crammed with toxins. Even standing underneath one during rainfall will cause blistering of the skin as a result of rain droplets mixing with its caustic sap.

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Drakea glyptodon -

This designer orchid encourages wasps to pollinate it by mimicking the shape of the Thynnine wasp. It smells absolutely awful to humans. 

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White snakeroot -

People are known to have died from drinking the milk or eating the meat of a cow that had ingested snakeroot, which contains a nasty toxin called tremetol.

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Angel's trumpet -

You'll end up blowing your own trumpet if you dare snack on this plant, which contains a host of chemicals, including scopolamine and atropine.

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Cerbera odollam -

The Cerbera's seeds contain a toxin called cerberin, which is no friend of the heart.

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Giant hogweed -

Brushing up against this towering and benevolent weed can be costly. Skin will color and blister, and eye exposure to the sap can lead to temporary blindness. 

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Rhododendron -

Some species of rhododendron are poisonous to grazing animals because of a toxin called grayanotoxin, which is found in their pollen and nectar. Similarly, humans have been known to fall ill after eating honey made by bees feeding on the flowers.

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Aconitum - A beautiful plant, but looks really can kill! Nicknamed the "queen of poisons," toxins extracted from aconitum can cause death within two to six hours of fatal poisoning.

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Autumn crocus -

Who would have guessed that such a delicate and pretty flower contains dangerous levels of colchicine, a toxic substance whose effects are similar to arsenic poisoning?

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Doll's eye -

The entire plant, including the toy-like berries, is considered poisonous to humans. In fact, the berries contain cardiogenic toxins, which can have an immediate sedative effect on cardiac muscle tissue.

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Delphinium - Also known as larkspur, the attractive dreamy blue appearance of this flower belies the cocktail of toxins found in the plant, including harmful alkaloids.

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Jimson weed -

Used in traditional medicine to treat asthma symptoms, the plant is a powerful hallucinogen and deliriant. Careless users run the risk of fatal overdose.

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Common laburnum - Celebrated for its luminous yellow, sweet-scented flowers, all parts of this attractive plant are nonetheless toxic, especially its seeds, easily mistaken for pea pods.

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European yew -

Accelerated heart rate, muscle tremors, convulsions, collapse, and difficulty breathing are all worrying symptoms of yew plant poisoning, although the flesh of the berries is not toxic.

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Poison ivy -

Touch this and expect an itchy, irritating, and occasionally painful rash. Blistered skin is not uncommon.

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Gympie Gympie -

The pain experienced after coming into contact with the prickly hair covering the entire plant is nothing short of excruciating, a sensation similar to being burned by acid.

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Poison sumac - Skin contact with the oil of a poison sumac plant leads to an itchy, burning allergic skin reaction.

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Poet's narcissus - All narcissi are poisonous when eaten but this daffodil is particularly dangerous. Its powerful scent can also cause vomiting and nausea.

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Lily of the valley - Innocuous enough in name and nature, the plant does however contain deadly saponins. Despite this, herbalists use these in moderate amounts to make herbal remedies.

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The corpse flower - Known for its awful stench, a smell akin to rotting flesh, the aptly named corpse flower is at its most potent from late evening until the middle of the night.

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Castor oil plant -

Guinness World Records lists this plant as the most poisonous in the world. A toxic superstar, its beans contain alkaloid ricin and toxalbumin ricin. Just one milligram of ricin can end an adult's life.

See also: Fruit and veggies you won't believe are man-made.

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