Citrus × aurantiifolia

The Key lime, also known as West Indian Lime, Mexican Lime or Egyption Lime (Citrus × aurantiifolia or C. aurantifolia) is a type of lime. While it is treated as a species in botanical classification, it originated as a natural hybrid between: Citrus micrantha (a wild papeda) and Citrus medica (citron). The Key lime has thinner rind and is smaller, seedier, more acidic and more aromatic than the Persian lime (Citrus × latifolia). It is valued for its characteristic flavor. The name comes from its association with the Florida Keys, where it is best known as the flavoring ingredient in Key lime pie. The key lime is not to be confused with bartender's lime or Omani lime, which are slightly different. The last is classified as a distinct race with a thicker skin and darker green colour. Philippine varieties have various names, including dayap and bilolo....read more on Wikipedia.