Nutmeg is the seed or ground spice of several species of the genus Myristica. Myristica fragrans is a dark-leaved evergreen tree cultivated for two spices derived from its fruit: nutmeg, from its seed, and mace, from the seed covering. It is also a commercial source of an essential oil and nutmeg butter. Conifers of the genus Torreya, commonly known as the nutmeg yews, have seeds of similar appearance, but are not closely related to Myristica fragrans, and are not used as a spice. Indonesia is the main producer of nutmeg and mace.
If consumed in amounts exceeding its typical use as a spice, nutmeg powder may produce allergic reactions, cause contact dermatitis, or have psychoactive effects. Although used in traditional medicine for treating various disorders, nutmeg has no scientifically confirmed medicinal value.