Young Blonde Girl With The Orange Fruit

Navel oranges are characterized by the growth of a second fruit at the apex, which protrudes slightly and resembles a human navel. They are primarily used for eating, as the skin is thicker and easier to peel than a common orange, they are less juicy, and a bitterness from limonin during processing renders them less satisfactory for juice. They are very popular because of their use as an eating orange, their widespread distribution, and their long growing season; in the United States, they are available from November through April, with peak supplies in January, February and March.
According to Dorsett, Shamel, and Popenoe (1917) of the U.S. Department of Agriculture who conducted a study at first hand, a single mutation in 1810 to 1820 in a Selecta orange tree planted at a monastery near Bahia in Brazil, probably yielded the navel orange, also known as the Washington, Riverside, or Bahia navel. However, a researcher at the University of California, Riverside, believes that the parent variety was more likely the Portuguese navel (Umbigo) orange described by Risso and Poiteau (1818–22). The mutation causes the orange to develop a second orange at the base of the original fruit, opposite the stem, as a conjoined twin in a set of smaller segments embedded within the peel of the larger orange. From the outside, it looks similar to the human navel, hence its name.
Because the mutation left the fruit seedless, and therefore sterile, the only means available to cultivate more of this new variety is to graft cuttings onto other varieties of citrus tree. It was introduced into Australia in 1824 and Florida in 1835. Twelve such cuttings of the original tree were transplanted to Riverside, California in 1870, which eventually led to worldwide popularity. The California Citrus State Historic Park preserves this history in Riverside, California, as does the Orcutt Ranch Horticulture Center in Los Angeles County, California.
Today, navel oranges continue to be produced through cutting and grafting. This does not allow for the usual selective breeding methodologies, and so not only do the navel oranges of today have exactly the same genetic makeup as the original tree, and are therefore clones, all navel oranges can be considered to be the fruit of that single nearly two-hundred-year-old tree. The case is similar to that of the common yellow seedless banana, the Cavendish. On rare occasions, however, further mutations can lead to new varieties.