Curare is a general name for a number of plant-derived poisons known to be used by South and Central American tribes. Curare is an alkaline poison, meaning that the poison is basic in pH, or exists above a pH of 7. There are many plants from which curare can be derived, as many plant poisons have evolved to defend the plants from attack from mammalian herbivores. Hunters from South American tribes often used this to their advantage by tipping their arrows in curare. The poison causes paralysis of the muscles and can eventually lead to death if the diaphragm becomes paralyzed.