MACE / SEMPRA Mace is the waxy outer layer that surrounds the seed of the nutmeg. The webbing around it is known as an "aril." The center of the nutmeg contains the single, hard seed. Mace is often called the sister spice of nutmeg for their relation to each other in how they grow on the nutmeg tree. In fact, nutmeg trees are the only plant to produce two spices from a single plant. Though similar in taste, mace has a flavor profile that is not quite as sweet as nutmeg and offers a sharper note of a bitter finish. Additionally, mace has more of a pepper-like finish to it, and notes of pine and coriander with citrus.