Lemons are the citrus fruit from the tree Citrus X limon. They are cultivated primarily for their juice, though the pulp and rind are also used, primarily in cooking or mixing. Lemon juice is about 5% citric acid, which gives lemons a sour taste.
This is a small tree, to 6 m (20 ft) but usually smaller. The branches are thorny, and form an open crown. The leaves are elliptical–acuminate. Flowers are violet and streaked in the interior and white on the outside.
The first description of the lemon, which had been introduced from India two centuries earlier, is found in Arabic writings from the 12th century. More recent research has identified lemons in the ruins of Pompeii. The origin of the name lemon is Persian (from Persian لیمو Limu). They were cultivated in Genoa in the mid-fifteenth century, and appeared in the Azores in 1494. Lemons were once used by the British navy to combat scurvy, as they provided a large amount of vitamin C. The British navy originally thought lemons were overripe limes which they resemble and their sailors became known as limeys, not lemonys.
Both lemons and limes are regularly served as lemonade (natural lemon with water and sugar) or limeade, its equivalent, or as a garnish for drinks such as cola with a slice either inside or on the rim of the glass. Lemon juice is typically dripped onto battered fish dishes in restaurants in the United Kingdom and other countries — the acidic juice neutralizes the taste of amines in fish. Some like to eat lemons as fruit. One unusual use of lemon juice is as the main ingredient of an oil substitute for cars.
Propogation is by grafting as the stock is vunerable to cankers and dry rot.
Lemon juice contains approximately 500 milligrams of vitamin C and 50 grams of citric acid per liter.