The Seville orange, also known as bitter orange or Citrus aurantium, is a type of citrus fruit native to Southeast Asia. It is characterized by its thick, bumpy skin and sour flavor, making it less suitable for eating raw. Instead, it is commonly used in cooking, marmalades, and liqueurs, such as Grand Marnier. This orange is particularly famous for its role in making marmalade, a sweet spread that combines the fruit's juice and peel with sugar. The Seville orange is typically harvested in winter and early spring, and its unique taste adds a distinct flavor to various culinary dishes and beverages.