Citrus History

Oranges are often said to be a wholesome, natural, and tasty thing to eat. But just what is “natural?” The history of the orange and it’s acidic friends is a scientific adventure through prehistoric genetic engineering and cultural trade.

It is commonly accepted that there are four founding species of the citrus genus:

• Lime (Citrus aurantifolia)
• Pummelo (Citrus maxima)
• Citron (Citrus medica)
• Mandarin (Citrus reticulata)

The citron was the first of the citruses to be known in Europe. Having been introduced to Europe by Alexander the Great’s armies, it was used first as a perfume and then as a food. The lime was introduced to Europe during the crusades. The pummelo was introduced at about the same time, and the mandarin was last to be introduced to Europe, in the 19th century.

These fruits were commercially grown in China for thousands of years, then introduced to Europe through trade. But three of the most popular citrus plants today are all plants that were invented by humans through hybridization:

• Lemon, Citrus limon (citron × lime, invented in India)
• Grapefruit, Citrus paradisii (pummelo × orange, invented in Barbados)
• Orange, Citrus sinensis (pummelo × mandarin, invented somewhere in Southeast Asia)

Portuguese, Spanish, Arab, and Dutch sailors planted lemon trees along trade routes to prevent scurvy. On his second voyage in 1493, Christopher Columbus brought the seeds of oranges, lemons and citrons to Haiti and the Caribbean. Oranges and lemons were introduced to Florida in 1513 by Juan Ponce de Leon, and were introduced to Hawaii in 1792.

Island of Barbados

In the early 1700s Captain Shaddock invented the grapefruit on the island of Barbados by mixing the Jamaican sweet orange with the Indonesian pomelo plant. The “Shaddock” over time became the “grapefruit,” an allusion to the clusters of fruit on the tree, which often appear similar to grapes. In 1929 the red grapefruit was invented after a single red grapefruit was found growing on a pink variety tree. Over time this variety was bred into commonality and patented.

The conjoined twin of the navel orange, seen bottom right.

But by far the most interesting story of human invention regarding the citrus is the story of the navel orange. Navel oranges are one of the most common and easily recognizable types of fruit, due to the fact that it is actually two oranges living in one shell. Every navel orange contains a conjoined twin inside it. The bump created by this conjoined twin bears resemblance to a human navel.

From a single mutation in 1820 in an orchard of sweet oranges planted at a monastery in Brazil came the navel orange. Every navel orange plant in existence today has been genetically cloned from the original 19th century tree.

Because the delicious and interesting mutation left the fruit seedless, and therefore sterile, the only means available to cultivate this variety is to graft cuttings onto other varieties of citrus tree. Grafting is the process of cutting part of a living organism off and transplanting it to the open wound of another organism, fusing them together. Two cuttings of the original tree were transplanted by ship to Riverside, California in 1870.

Today, navel oranges continue to be produced via cutting and grafting. Every navel orange has exactly the same genetic makeup as the original two hundred-year-old tree. They are clones, and in essence are all the fruit of a single tree. When you bite into a fresh navel orange, grapefruit, lemon, or even if you are fortunate enough to be eating a lime outside of China, realize that you are eating something entirely of human invention.

Lineage:

• Guns, Germs, and Steel, by Jared Diamond
• http://inamidst.com/notes/citruses
• Wikipedia: Grapefruit
• Wikipedia: Orange