Lemon is a tree that belongs to the Rutaceae family and is also the name of the fruit itself. The lemon is not a naturally-occurring species, but a hybrid between different varieties of the Citrus family.

The lemon grows on a thorny bush or small tree that grows between 3 and 6 metres high. The fruit is oblong or rounded and yellow in colour when ripe. Its flesh is highly acidic.

It is mainly cultivated for its fruit juice, which contains high levels of citric acid that give it its sour taste. Both lemons and limes are used in food and beverages but they are also eaten raw. The finely grated peel is known as lemon zest.

The skin has two layers. The outer layer, which is leathery, contains many esoteric oils and pigments varying from yellow to orange to green. The inner layer (pith) is white, contains pectin and is rich in vitamin C. The pulp, which is divided into segments, contains vitamins, citric acid and minerals.