A lime (from french lime, from arabic līma, from persian līmū, "lemon") is a citrus fruit, which is typically round, green in color, 3–6 centimetres (1.2–2.4 in) in diameter, and contains acidic juice vesicles.there are several species of citrus trees whose fruits are called limes, including the key lime (citrus aurantiifolia), persian lime, makrut lime, and desert lime. limes are a rich source of vitamin c, are sour, and are often used to accent the flavours of foods and beverages. they are grown year-round. plants with fruit called "limes" have diverse genetic origins; limes do not form a monophyletic group.

Source: Wikipedia