The Key lime (Citrus aurantiifolia (often abbreviate to: C. aurantiifolia), or Citrus x aurantiifolia (Christm.) Swingle), also known as the Mexican lime, West Indian lime or Bartender's lime, has a globose fruit, 2.5-5 cm in diameter (1-2 in), that is yellow when ripe but usually picked green commercially. It is smaller, seedier, has a higher acidity, a stronger aroma, and a thinner rind than that of the Persian lime (Citrus x latifolia). It is valued for its unique flavor compared to other limes, with the key lime usually having a more tart and bitter flavour. The name comes from its association with the Florida Keys, where it is best known as the flavouring ingredient in Key lime pie.