The trees are cultivated in tropical regions worldwide. Enough varieties have been developed to warrant classification of this single species into 4 groups based on geographical ancestry and fruit characteristics.
Blood oranges have dark red pulp and juice of excellent flavor.
Navel oranges are a modern introduction especially appropriate for eating fresh because of their easy to peel skins and lack of seeds. Sweet orange oil can be extracted from any of these but is most often a by-product of Mediterranean and Spanish oranges grown for the juice industry. The oil found in the peel of the famous Valencia orange, a Spanish variety, is typical of the kind of sweet orange oil found on the market today. The isolation of sweet orange oil and orange juice pose a challenge for producers. Unless the two are extracted cleanly and separately from each other, the quality of both will be diminished.