There are several species of citrus trees whose fruits are called limes, including the Key lime (Citrus aurantiifolia), Persian lime, kaffir 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.
The difficulty in identifying exactly which species of fruit are called lime in different parts of the English-speaking world (and the same problem applies to homonyms in other European languages) is increased by the botanical complexity of the citrus genus itself, to which the majority of limes belong. Species of this genus hybridise readily, and it is only recently that genetic studies have started to throw light on the structure of the genus. The majority of cultivated species are in reality hybrids, produced from the citron (Citrus medica), the mandarin orange (Citrus reticulata), the pomelo (Citrus maxima) and in particular with many lime varieties, the micrantha (Citrus micrantha).
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. British sailors thus acquired the nickname "Limey" because of their use of limes.
In 2018, world production of limes (combined with lemons for reporting) was 19.4 million tonnes. The top producers – India, Mexico, China, Argentina, Brazil, and Turkey – collectively accounted for 65% of global production.
Lime pickles are an integral part of Indian cuisine. South Indian cuisine is heavily based on lime; having either lemon pickle or lime pickle is considered an essential of Onam Sadhya.
Lime is an ingredient of many cuisines from India, and many varieties of pickles are made, e.g. sweetened lime pickle, salted pickle, and lime chutney.
Lime is an ingredient in several highball cocktails, often based on gin, such as gin and tonic, the gimlet and the Rickey. Freshly squeezed lime juice is also considered a key ingredient in margaritas, although sometimes lemon juice is substituted. It is also intimately associated with many rum cocktails such as the Daiquiri, and tropical drinks - especially within the Tiki culture.
Raw limes are 88% water, 10% carbohydrates and less than 1% each of fat and protein (table). Only vitamin C content at 35% of the Daily Value (DV) per 100 g serving is significant for nutrition, with other nutrients present in low DV amounts (table). Lime juice contains slightly less citric acid than lemon juice (about 47 g/l), nearly twice the citric acid of grapefruit juice, and about five times the amount of citric acid found in orange juice.
A class of organic chemical compounds called furanocoumarins are reported to cause phytophotodermatitis in humans. Limes contain numerous furanocoumarin compounds, including limettin (also called citropten), bergapten, isopimpinellin, xanthotoxin (also called methoxsalen), and psoralen. Bergapten appears to be the primary furanocoumarin compound responsible for lime-induced phytophotodermatitis.