Navel orange
The navel orange is a variety of orange with a characteristic second fruit at the apex, which protrudes slightly like a human navel. This variety first was caused by a mutation in an orange tree, and first appeared in the early 19th century at a monastery in Bahia, Brazil.<ref name=":1">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The mutation caused the orange to develop a second fruit at its base, opposite the stem, embedded within the peel of the primary orange.<ref name=":0">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> This mutation also caused it to be seedless,<ref name=":1" /><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> meaning the only way the plant can be propagated is by cutting and grafting.<ref name=":0" /><ref name="cfaitc">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Navel oranges are mainly an eating fruit because they are seedless and their thicker skin makes them easy to peel.<ref name="Kimball">Template:Cite book</ref> They are also less suitable for juice than other orange varieties as they are less juicy, and because their flesh contains limonin, which becomes bitter when exposed to air.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
HistoryEdit
The navel orange originated in Bahia, Brazil in the 1810s or 1820s.<ref name=":1" /><ref name=":0" /> This variety was likely the Portuguese navel orange or Umbigo described by Antoine Risso and Pierre Antoine Poiteau in their 1818–1822 book Histoire naturelle des orangers ("Natural History of Orange Trees"). Because of the perceived superiority of this new cultivar, the orange was introduced to Australia in 1824 and Florida in 1835.<ref name="Washington on Citrus ID">{{#invoke:citation/CS1|citation |CitationClass=web }}, citing amongst other sources Template:Cite book</ref>
In the 1870s, the newly formed United States Department of Agriculture (USDA) imported twelve navel orange trees from Brazil to Washington, D.C.<ref>Template:Cite journal</ref> Two of these cuttings were sent to Eliza Tibbets in 1873, who planted them in Riverside, California, where the fruit became known as "Washington".<ref name="Washington on Citrus ID" /><ref>Saunders, William "Experimental Gardens and Grounds", in USDA, Yearbook of Agriculture 1897, 180 ff; USDA, Yearbook of Agriculture 1900, 64.</ref>
The Cara Cara is a type of navel orange grown mainly in Venezuela, South Africa and California's San Joaquin Valley. It is sweet and low in acid,<ref name="UBC">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> with distinctively pinkish red flesh. It was discovered at the Hacienda Cara Cara in Valencia, Venezuela, in 1976.<ref name="UCR">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>