Citrus is the general name for a group of species and hybrids that includes Lemons, Oranges, Mandarins, Grapefruit and many others.
Citrus fruits are the most valuable fruit crop in international trade. All of the numerous Citrus varieties are cultivated in subtropical or tropical regions. Oranges were already being used in China in 2000 BC, while the Seville orange (also known as the bitter or sour orange) was first grown in northern India. The lemon comes from the eastern Himalayas; mandarins, however, probably derive from the Mediterranean.
Today, citrus is cultivated in 140 countries. More than two-thirds of global citrus production is done in Brazil, USA, China, Mexico and Spain. In Brazil and the USA, about 70% of the harvest is used for processing, whereas the Mediterranean countries produce mostly for fresh consumption, supplying primarily the European market. In Asia, most of the citrus produced is consumed domestically.