Nutmeg's sister spice is mace. The only plant that provides us with two spices is the nutmeg tree. (In contrast to dill, a plant that provides us with a spice and an herb.) While mace is what is referred to as an airl—the seed's protective coating—nutmegs are the tree's actual seeds.

Since mace's flavor and aroma tend to be sharper and less sweet than nutmeg, they are slightly different from each other. It still tastes strongly of nutmeg, but there are also faint hints of pine, black pepper, and citrusy flavors resembling coriander. Despite coming from the same plant, the essential oils of mace and nutmeg have different chemical makes up and distinct flavors. Similar to how the peel of an orange has a different flavor and aroma from the flesh, so does this.