The Citrus sinensis is the sweet orange, the fruit of a subtropical tree. It probably originated in Southeast Asia, most likely from a hybrid; no wild oranges have been found. Like all citrus, the orange is a member of one large species that can be crossbred with any other member, from the kumquat to the grapefruit.
The flesh of the Blood orange is streaked with colors that vary from pinkish to maroon. They taste (especially the Moro variety) like orange mixed with raspberry, and are available in the U.S. in late winter.
The sour Persian orange was probably the first orange widely available in Europe. They mostly fell out of favor once sweeter oranges were grown.
The Navel orange was a spontaneous mutation that arose on a Brazilian plantation in 1820. Instead of seeds, it has a small, undeveloped conjoined twin at the blossom end of each fruit. Since it is seedless, the navel orange can only be reproduced by cloning. All the navel orange trees in the world originate from grafts from earlier navel orange trees.
The Cara Cara is a particularly sought-after variety of navel orange. They look ordinary on the outside, but the inside is salmon pink, and the juice has an tinge of strawberry scent.
Valencia oranges have no navel, but do have seeds. They are the big juicy oranges that are available most of the year, but are particularly plentiful in summer.
Oranges are a popular food. They appear in juice, salad, and many desserts. They are valued for their vitamin C content, which prevents or treats the vitamin deficiency known as scurvy, and supply small amounts of some B vitamins and other nutrients.
Orange blossoms are processed into neroli, a spicy sweet flowery aroma, by steam distillation, and used in many perfumes. Orange flower water is a similar essence, often used in food. Petitgrain oil is a floral essence distilled from orange leaves and twigs. It is similar to neroli, but with woody overtones. It is also used in perfumery and aromatherapy. Sweet orange oil is processed from orange skins, and often used in household cleaners.
Delicate orange blossoms are often worn by brides, or carried in their bouquets. They are considered a symbol of purity as well as a good luck talisman.
Oranges are berries. (So are tomatoes, pomegranates and watermelons.) This may explain why the taste of certain oranges carries an undertone of berry flavor. Technically any citrus fruit is a hesperidium, a berry with a leathery rind. The fleshy interior is called the endocarp, and has multiple sections, carpels, filled with vesicles, specialized hair cells that develop into sacs filled with juice.
Oranges may have been the “golden apples of the sun” that grew in the Garden of the Hesperides in Greek mythology. Eating them restored youth in the myth, as eating actual oranges restores health to people suffering from scurvy.