Marjoram ( Origanum majorana , Lamiaceae ) is a somewhat cold-sensitive perennial herb or undershrub with sweet pine and citrus flavors . In some middle-eastern countries , Marjoram is synonymous with Oregano , and there the names Sweet Marjoram and Knotted Marjoram are used to distinguish it from other plants . Oregano ( Origanum vulgare , sometimes listed with Marjoram as Origanum majorana ) is also called Wild Marjoram .