One of the most deadly plants is poison hemlock , which grows throughout the world. It belongs to the carrot and celery family, but don't let that fool you. All parts of this plant carry a very powerful poison.
People have died by mistaking the leaves for parsley and the roots for carrots. Luckily, poison hemlock has a bitter taste and smells like cat pee, so few people ever eat it.
Some close relatives, called water hemlocks, can also be deadly. Eating just one piece of root could kill an adult. And some children have been poisoned by using the plant's hollow stems as pea-shooters.