The most common type of orange is the navel orange, known for its sweet and seedless flesh. Navel oranges are easy to peel and are popular for snacking or juicing.
Washington navel orange
Navel Orange.
Its end looks like a navel, which is a bellybutton
I believe that what you're thinking of is a grapefruit. Yes, the blood orange can be purple in color inside. It is a less popular fruit than it's more well known navel cousin. The blood orange is an older species of fruit than the navel orange.
A navel orange is a special type of orange which has a little surprise inside once it is peeled: a partially formed undeveloped fruit like a conjoined twin, located at the blossom end of the fruit. From the outside, the blossom end is reminiscent of a human navel, leading to the common name of "navel orange." These oranges are cultivated primarily in Brazil, California, Arizona, and Florida, and they are among the most common and popular of orange varieties. You may know the navel orange as a Washington, Riverside, or Bahia Navel Orange. If you're in a formal mood, you can call it by its scientific name, Citrus sinensis. This orange varietal is the result of a single mutation which occurred on a plantation in Brazil in 1820. The mutation led to the formation of a conjoined twin enclosed within the rind of a seedless orange, and it proved to be a hit, so people began cultivating it in other regions. The first American location of cultivation was Riverside, California, explaining the alternate name of "Riverside Orange." Because the navel orange is seedless, it can only be propagated through cuttings. Technically, every navel orange comes from the same orange tree; the Brazilian orange which generated a spontaneous mutation hundreds of years ago. Orange farmers take cuttings from their navel orange trees and grat them onto fresh stock periodically to ensure that their orchards stay healthy, and also for the purpose of expansion.
Navel oranges are considered to be the finest eating orange in the world. A navel orange is seedless.
blood orange
There was an orange tree that developed a deformation in the fruit, so that it would not bear seeds. It was a complete accident, but now the naval orange is very popular. It is only grown from clippings, because the fruit has no seeds.
Navel oranges are generally considered sweeter than Valencia oranges. Navel oranges have a higher sugar content and a lower acidity level, which contributes to their sweet flavor. Valencia oranges, while still sweet, tend to have a slightly more tart taste, making them popular for juicing. Overall, if you're looking for sweetness, Navel oranges are the better choice.
A seedless orange is called a navel orange. Navel oranges are characterized by the small undeveloped secondary fruit embedded at one end, resembling a human navel. This small fruit is sterile, resulting in seedless varieties.
Some popular seedless orange varieties include navel oranges, blood oranges, and cara cara oranges.