Curare is a common name used for various alkaloid poisons originating from plant extracts. Traditionally it has been used as a paralysing agent by indigenous peoples in Central and South America when hunting or for therapeutic purposes. These poisons cause weakness of the muscles and will, when administered in a sufficient dose, eventual death by asphyxiation due to paralysis of the diaphragm. As curare only becomes active when it contaminates a wound, it is commonly used while hunting with bow and arrow or blowpipe and the tips of the arrows and darts dipped in the substance.
In An Autobiography, Christie describes how a certain senior pharmacist she was training under, one Mr P carried a piece of curare in his pocket because it made him feel powerful. While Christie made use of a wide range of poisons in her stories, curare is never used as a means of murder. In Death in the Clouds trace elements of curare were found on the murder weapon but it wasn't the direct cause of death. The murder weapon had been dipped into a snake venom.