There are now six main categories of orange in cultivation.
Common sweet oranges exist in numerous varieties. Saunt (1990) explains that Valencia, the most important variety of all, is not an old Spanish one, as might be supposed, but ‘first became of interest in the Azores and is almost certainly of old Portuguese origin’. It seems that it was sent from the Azores in the early 1860s to Thomas Rivers at Sawbridgeworth in England, who first named it Excelsior and sent it to the USA where it was renamed several times, finishing up as Valencia Late—this because a Spanish citrus expert visiting California thought it closely similar to a late-maturing variety grown in Valencia in Spain. This variety leads production in both California and Florida and in many of the main orange-growing countries, but not in Spain itself. Oranges of this variety have a thin rind, not difficult to peel at maturity, plenty of juice of a good colour, and usually two to four seeds.