Navel oranges were the foundation of the Southern California produce industry. In the mid 1800's, the first citrus farm was established in what is now downtown Los Angeles, setting the scene for a rich and vibrant history of citrus in California. Originally introduced to Riverside, California from Brazil in 1873, the navel orange tree became world famous for richly sweet, nearly seedless, brightly colored fruits. Navel oranges traveled great distances across the first trans-continental railroad, making it possible for people across the country to have a taste of California sunshine. This iconic orange tree variety propelled the economic development of early California, and established California's reputation as a world-class growing site.
Navel oranges provide an important source of vitamin C and other nutrients in the middle of the winter, when few other types of fruit are in season. They are ideally suited to growing in only a few mild-winter areas of the United States including Central to Southern California, Southern Florida, and Southern Texas. They can be grown in other areas, but usually with special care, with only limited species and varieties, or in containers for indoor growing during cold winters. Today, oranges and other citrus are so common in parts of Southern California that they sometimes go unappreciated or even ignored. Historic orange tree groves are commonly razed to make way for suburban and peri-urban development projects, which ironically often lack spaces for residents to garden and or have access to fruit trees.
Oranges are small trees in the Citrus genus and the family Rutaceae, the rue family, with many of its numerous plant members known for producing strongly aromatic, flavorful, or medicinal leaves and/or fruit. Sweet oranges, and sweet citrus in general, require heat to develop high sugar content in fruits; while sour oranges, and sour citrus in general, are often able to produce good-quality fruit in cooler climates. Southern California has the perfect climate for navel oranges to develop both sweetness and brilliant color.
Navel oranges are known for a distinctive, immature fruit that is formed on the blossom side of each fruit in a small depression. They have a thicker skin than other types of sweet oranges, and are easy to peel. By far, the most common and well known type of navel is the Washington navel (sometimes called Riverside or Bahia navel). However, there are a number of other navel varieties with varying maturation times and qualities that have derived as mutations from the original variety. Other varieties include the Cara Cara, a deliciously fruity and rosy fleshed orange. Lane late is a bit smaller, and smoother skinned, ripening almost a month later than classic Washington navels. Other varieties include the Robertson, Skaggs Bonanza, and the Fukumoto.
Oranges are known for their high vitamin C content, but also contain dietary fiber, thiamin, and potassium. One medium-sized orange can contain up to 100% or more of the USDA recommended daily vitamin C.