Two types of limes are available: Key limes grown in the Florida Keys and the more common Persian limes. Here’s what you need to know: Florida key limes (aka Mexican limes or West Indian limes) tend to be smaller and have a distinct, slightly floral lime flavor that is tart but not too acidic. They contain more seeds and have thinner, yellowish skin than regular limes. Persian limes are larger and tarter than their Florida cousins. They have firm, bright green peel and are often seedless. This is the type of lime generally sold in grocery stores. Cook’s Illustrated compared the flavors of key lime vs. Persian limes and noted that “Key lime juice tasted slightly less tart and bracing than its Persian counterpart.” They even confirmed this with a lab test, which showing that Persian limes have a higher acidity than key limes.