Citrus limonia, commonly known as the rough lemon, is a hybrid citrus fruit believed to be a cross between the lemon and the citron. It is characterized by its bumpy, thick skin and acidic flavor. The fruit is typically smaller than regular lemons and is often used in cooking and beverages for its tartness. This species is primarily grown in tropical and subtropical regions, where it thrives in warm climates. Citrus limonia is also valued for its ornamental qualities and is sometimes used as a rootstock for other citrus trees, enhancing their resilience and fruit production.