In the U.S., oranges are considered to be seedless if they have from zero to six seeds, according to Purdue University's Horticulture and Landscape Architecture website. Because we view seeds as a nuisance when eating fresh oranges, breeders in the 1800s developed trees producing seedless varieties. These varieties are propagated by taking cuttings from a tree and grafting them onto root stock. A seedless orange is produced when the flowers from which the fruit develop are not pollinated, as the anthers do not develop pollen. The most popular varieties of seedless oranges for eating fresh are naval, Valencia and Jaffa.The Tarocco is Italy's favorite seedless orange.
Imported from Brazil to Washington, D.C. in 1870, the navel orange was introduced into Florida and California. All navals are descended from a single seedless orange tree from a Brazilian plantation. It is now the leading fresh orange variety in the United States, according to the "Oxford Companion to American Food and Drink." Naval oranges are seedless, large, easy to peel with a thick skin and easy to segment. Offering high levels of both acidity and sugars, they are prized for their sweet, rich and delicious juice. Like all oranges, navals are high in vitamin C.
Nearly seedless, the Valencia orange is known for its juiciness and rich flavor. Smaller than a naval, Valencia oranges have a thinner rind making them a bit harder to peel, but many orange lovers prefer them over the slightly drier naval. Avoid Valencia oranges from Chile if you don't like seeds.
Europe's Favorite Seedless
Sometimes called Shamouti, Jaffa oranges make up 75 percent of the Lebanese and Israeli crops, according to Purdue Univeristy's Horticulture and Landscape Architecture website. The Jaffa is known for its fragrant and pleasantly sweet flavor and is popular among Europeans. It's also an easy fruit to peel and segment.
Italy's Favorite Seedless
Popular in Italy and the Mediterranean, the Tarocco orange is shaped similarly to a tangelo. This seedless fruit has a rich, juicy, raspberry flavor and the perfect balance between sweetness and acidity. The original mutation that produced this seedless variety came from Sicily in the 17th century. Called a blood orange, it has hints of red in the flesh.