Sweet orange is an evergreen tree of Oriental origin, 4 to 6 m (13 to 20 ft.) high. It has a cylindrical trunk, alternate leaves, and odorous flowers and fruits. The fruit has a green epicarp that turns yellow on ripening; a white, spongy mesocarp; and an endocarp consisting of succulent segments bearing seeds. The Mediterranean countries in which it is cultivated include Italy (Sicily, Calabria, and Campania), Algeria, Tunisia, Morocco, Spain, and Israel; in addition, very important production occurs in California and Florida. It has an enormous worldwide economic importance. In the various countries, cultivation is geared toward the production of (1) fruits for immediate consumption and (2) fruits to be used for the production of juices or essential oils. For this purpose, the most suitable varieties have been selected. The parts used are the leaves (and small twigs), flowers, ripe fruits, small, whole, unripe fruits, peels, and juice. The oils and various derivatives from orange, sweet have a mild to highly bitter, astringent flavor and a characteristic aroma. The juices are sweet and acidic or tart. Petitgrain essential oil of sweet orange can be obtained from the leaves, small, whole unripe fruits, twigs, and flowers by steam distillation. Its production is low because of its limited application (perfumery). Sweet orange essential oil is extracted from the peels of partially ripened fruits in 0.4 to 0.5% yields using suitable machinery fpr the rupturing of the oil-bearing cells (expression). A less valuable quality of essential oil is obtained by steam distillation of peels.