Nutmeg is not poisonous to people when consumed in normal amounts. It is a spice that is the seed of the nutmeg tree, a tropical evergreen that grow on the Spice Islands.The fruit of the tree produces mace which is ground from the dried fibrous meat of the fruit and the nutmeg seed which is used whole or ground. Nutmeg contains a narcotic called myristicin.In large doses (a full teaspoon or more of ground nutmeg, or 1-3 whole nutmegs) at one time, nutmeg can be poisonous or even hallucinogenic, and cause nausea, vomiting and circulatory collapse. Nutmeg is also poisonous to dogs.t is a spice that is the seed of the nutmeg tree, a tropical evergreen that grow on the Spice Islands. The fruit of the tree produces mace which is ground from the dried fibrous meat of the fruit and the nutmeg seed which is used whole or ground. Nutmeg contains a narcotic called myristicin.