Key lime pie is an American dessert pie made of Key lime juice, egg yolks, and sweetened condensed milk in a pie crust. The traditional Conch version uses the egg whites to make a meringue topping. The dish is named after the small Key limes (Citrus aurantifolia 'Swingle') that are naturalized throughout the Florida Keys. While their thorns make them less tractable, and their thin, yellow rinds more perishable, Key limes are more tart and more aromatic than the common Persian limes seen year-round at grocery stores in the United States. Key lime juice, unlike regular lime juice, is a pale yellow. The filling in a Key lime pie is also yellow, largely because of the egg yolks. Sponge divers at sea would presumably not have access to an oven, and, similarly, the original recipe for Key lime pie did not call for cooking the mixture of lime, milk, and eggs.