Nutmeg is the seed or ground spice of several species of the genus Myristica. Myristica fragrans (fragrant nutmeg or true nutmeg) 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. The California nutmeg, Torreya californica, has a seed of similar appearance, but is not closely related to Myristica fragrans, and is not used as a spice. Indonesia is the main producer of nutmeg and mace.