This fiendish plant is an evil cousin of the also-rather-deadly poison hemlock, better known as the plant that killed Socrates. Water hemlock is a large wildflower in the carrot family, but don’t mistake it for a tasty vegetable or you’ll end up chowing down on a whole load of cicutoxins. These cause nausea, convulsions, abdominal cramps, amnesia and death.
Deadly nightshade
The clue’s in the name. Deadly nightshade truly is deadly, but the sweetness of its berries (which are about the size of cherries) has unfortunately proved tempting to those unaware of its murderous nature. Legend says that the soldiers of 11th century King of Scotland Macbeth created toxic wine from nightshade to poison Danish invaders.
Stinging tree
Common stinging nettles might be a bit ouchy, but this Australian plant is the most potent nettle in the world. Just brushing against it can cause a painful sting that lasts for months, and severe encounters have been known to kill humans.
Manchineel
Often marked with a red X to warn people of its evil qualities, manchineel trees produce a milky sap that leaves skin horribly blistered. Sheltering under it during a rain storm leads to terrible consequences: the rainwater that lands on its leaves and falls on to those below will cause extreme, burning rashes.
Castor bean
Castor beans are the source of the pharmaceutical ingredient castor oil, but also contain a nasty toxin: ricin. This stuff’s truly deadly—it causes severe vomiting, diarrhoea, seizures and death. Ingesting as few as two castor beans can be enough to kill a child.
White snakeroot
Another infamous killer. White snakeroot is so poisonous that you can die simply from drinking the milk of a cow that’s eaten it. This was the unfortunate fate met by Abraham Lincoln’s mother, Nancy Hanks. Eating beef from a cow that’s consumed snakeroot can also kill you.
Rosary pea
These beautiful but bothersome seeds are sometimes used in jewellery and prayer rosaries, hence the name. They contain a dangerous protein called abrin, three micrograms of which is enough to kill an adult. It explains why some jewellery makers die after pricking their finger while handling the plant.
Oleander
Commonly grown around the world for its its bright pink flowers, oleander isn’t just deadly when eaten. Smoke from a burning plant can also have fatal consequences. Its toxins are actually strong enough to be found in the honey made by oleander-visiting bees.
Monkshood
A notorious plant that goes by other villainous names including wolf’s bane, devil’s helmet and the queen of poisons, monkshood roots and leaves contain a neurotoxin that can be absorbed through the skin. Eating it is even worse, causing severe vomiting, diarrhoea and death.
Angel’s trumpet
These flowers are a joy to look at, but a nightmare to eat. Angel’s trumpets are filled with poison that’s deadly to both humans and animals. The substance can cause hallucinations, leading some people to try using it as a recreational drug. Trips are described as ‘terrifying rather than pleasurable’, and the chances of fatally overdosing are very high. Just say no.
Think plants are boring? These ones certainly aren’t. From trees that cause grotesque, burning blisters to poisonous plants capable of killing famous philosophers and Abraham Lincoln’s mum, here’s the fear-inducing flora that you’ll want to keep out of your garden.