The lemon is a deliberate genetic accident born from the union of the citron and the bitter orange. This hybrid species emerged during the first millennium BC in what is now northeastern India. No true lemon exists in the wild as every tree is a descendant of that ancient hybridization event.
In 1747, the English physician James Lind treated sailors suffering from scurvy by adding lemon juice to their diets. This discovery allowed ships to travel longer distances without losing crews to the disease, though the concept of vitamin C was unknown at the time. The British Navy eventually adopted lemon juice as a standard ration.
The juice of the lemon contains approximately 47 grams of citric acid per liter. This concentration is nearly twice that of grapefruit juice and five times that of orange juice. The high acidity level makes the fruit a powerful chemical agent capable of neutralizing amines in fish.
In 2024, the world produced 23 million tonnes of lemons, with India and Mexico leading the production and accounting for 31% of the total combined output. China and Argentina followed as secondary producers. The fruit's cultivation spread from its origins in India to the Americas in 1493 when Christopher Columbus brought lemon seeds to Hispaniola.
In Hindu tradition, a lemon is ritually encircled around a person to repel negative energies. It is common practice for new car owners to drive over four lemons, one under each wheel, to protect the driver from accidents. This belief in the fruit's protective power extends to its depiction in art from the 15th century tomb of Nakht in Egypt.