The name (bitter orange) also known as Seville orange, sour orange, bigarade orange, and marmalade orange, refers to a citrus tree (Citrus aurantium) and its fruit. Many varieties of bitter oranges are used for their essential oil, which is used in perfume and as a flavoring. Bitter orange is also used in herbal medicine as a stimulant and appetite suppressant, and has replaced the banned stimulant ephedra in many herbal weight-loss products.