The lemon is a hybrid, born from citron crossed with bitter orange
Every true lemon descends from a cross between citron and bitter orange, probably first arising in northeastern India during the first millennium BC. From there it travelled through Roman Italy, Islamic gardens and Columbus's ships to become a 23-million-tonne global crop, with juice sour enough to power a small digital watch.
Botanically the fruit is a hesperidium, a berry with a tough rind. The fragrant outer zest holds essential oils, the white pith sits beneath, and inside, segments are packed with juice vesicles. That juice is about 5 to 6 per cent citric acid, a touch more than lime juice and roughly five times as much as orange juice. Before fermentation processes took over, lemons were the main commercial source of citric acid.
The name travelled with the fruit, from Persian limun, a general word for citrus, through Arabic and Italian to Old French. Lemons reached southern Italy no later than the second century AD, then Persia, Iraq and Egypt around 700. A 10th-century Arabic farming treatise gives the first literary mention, when the trees decorated early Islamic gardens, and the agricultural expansion of 1000 to 1150 spread them across the Mediterranean. Genoa began serious cultivation in the mid-15th century, and in 1493 Columbus carried seeds to Hispaniola. James Lind's scurvy experiments of 1747 added lemon juice to sailors' diets before anyone knew of vitamin C.
Two cultivars dominate supermarket shelves. Eureka, nicknamed Four Seasons because it flowers and fruits all year, developed in 19th-century California from trees brought by Neapolitan and Sicilian immigrants during the Gold Rush. Lisbon, smoother and juicier, arrived with Portuguese settlers. Italy's Sorrento variety, rich in zest oil, is the traditional base for limoncello. Several fruits called lemons are other hybrids: the Meyer is a citron crossed with a mandarin–pomelo hybrid. In 2024 India and Mexico together produced 31 per cent of the world crop, counted jointly with limes.
Acid makes lemon useful beyond flavour. It tames fishy amines, loosens tough collagen in meat and stops sliced apples and avocados browning. Moroccan cooks cure whole lemons in salt so they keep almost indefinitely. In India some Hindu car owners drive over four lemons on a first outing as protection against accidents, and in modern English a defective car is itself called a lemon.
Source: Lemon
