Thinking back to the time your mother forced Castor oil down your throat, I bet you would never have guessed that it came from the most poisonous plant in the world (even if it did taste like it).Castor plants are indigenous to the Mediterranean basin, eastern Africa and India, but are widely grown as an ornamental plant. A toxin called ricin is found throughout the plant, but is concentrated in the seeds/beans (which castor oil is made from). One raw seed is enough to kill a human in 2 days, which makes for a long, agonizing and unstoppable death. The first symptoms will be experienced within a few hours and will include a burning sensation in the throat & mouth, abdominal pain, bloody diarrhea and vomiting. The process is unstoppable and the final cause of death will be dehydration.Strangely, humans are the most sensitive to these seeds, as it takes 1-4 to kill a full grown human, 11 to kill a dog and a whopping 80 seeds to kill a duck. The castor plant currently holds the Guinness World Record for most poisonous plant.