A lime is a hybrid citrus fruit, which is typically round, lime green, 3–6 centimetres (1.2–2.4 in) in diameter, and containing acidic juice vesicles.
There are several species of citrus trees whose fruits are called limes, including the Key lime, Persian lime, kaffir lime, and desert lime. Limes are an excellent source of vitamin C, 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.
Limes were first grown on a large scale in southern Iraq and Persia, and the fruit was first grown commercially in what is today southern Iraq (Babylonia).
To prevent scurvy during the 19th century, British sailors were issued a daily allowance of citrus, such as lemon, and later switched to lime. The use of citrus was initially a closely guarded military secret, as scurvy was a common scourge of various national navies, and the ability to remain at sea for lengthy periods without contracting the disorder was a huge benefit for the military. The British sailor thus acquired the nickname, "Limey" because of their usage of limes.