1 Castor oil plant – Listed by the Guinness Book Of World Records as the most poisonous plant on Earth, the ricin contained in one castor bean can easily finish off the average human.
2 Oleander – Don’t let its pretty blooms fool you – oleander contains potent glycosides which target the heart, provoking heart attacks in those who eat its flowers, leaves or fruit.
3 Rosary pea – The colourful seeds of Abrus precatorius are sometimes used to make jewellery, but they can poison handlers with abrin, a toxin which attacks protein-building ribosomes.
4 Belladonna – Also called deadly nightshade, this attractive plant contains a mix of alkaloids and was a popular poison in Ancient Roman times. Just one leaf is enough to kill a person.
5 Water hemlock – Native to North America, this plant contains cicutoxin, a neurotoxin which causes seizures, violent muscle contractions and loss of consciousness if ingested.