"The Key lime or acid lime (Citrus × aurantiifolia or C. aurantifolia) is a citrus hybrid (C. hystrix × C. medica) native to tropical Southeast Asia".Key Lime trees are everywhere
"The name comes from its association with the Florida Keys, where it is best known as the flavoring ingredient in Key lime pie".
I have to say, of all citrus fruits, the lime (from wheresoever it hails) is my favourite, particularly in lime pickle, that stuff I could eat with most dishes.
Jay.