In Mexico, Central America, the Caribbean, the Unite States, and Canada, a tortilla is a type of thin, unleavened flat bread, made from finely ground maize (corn) or wheat flour. A similar bread from South America is called arepa (though arepas are typically much thicker than tortillas). This form of bread predates the arrival of Europeans to America, and was called "tortilla" by the Spanish from its resemblance to the traditional Spanish round unleavened cakes and omelettes (originally made without potatoes, which are native to South America). The Aztecs and other Nahuatl-speakers called their tortillas by the name “tlaxcalli”: these have become the prototypical tortillas. The maize version is the original North American tortilla and is regarded by many as the "authentic" tortilla. Flour tortillas originated in regions of Mexico unsuited for growing corn.