In Colombia this fruit is called, limón mandarina. I am reading conflicting information on what the exact name is. In Spanish it is a hybrid between a lemon and mandarin. In English a hybrid between a citron and a mandarin (a rangpur). Anyway in Colombia the fruit is usually sold in the markets close to where it is cultivated with yellow skin (a rangpur has orange skin) and it has an orange pulp and is sweeter than a lime. Photographed in the Valley of Cauca.