Limes are sour, round, and bright green citrus fruits. They're nutritional powerhouses — high in vitamin C, antioxidants, and other nutrients. There are many species of limes, including the Key lime (Citrus aurantifolia), Persian lime (Citrus latifolia), desert lime (Citrus glauca), and makrut lime (Citrus hystrix). Limes have a tart, acidic taste with just a slight hint of sweetness. They're bright and vibrant, with a distinct zesty sour flavor, and their mouth-puckering bitterness is why they're not eaten whole like an orange.