Coniine is a poisonous alkaloid found in poison hemlock (Conium maculatum), the yellow pitcher plant (Sarracenia flava), and fool's parsley (Aethusa cynapium) and contributes to hemlock's fetid smell. It disrupts the peripheral nervous system and is toxic to humans and all classes of livestock; less than 0.1g is fatal to humans, with death caused by respiratory paralysis. Notably, Socrates was sentenced to death by drinking a mixture containing poison hemlock in 399 BC.