When my mind is jangled from too much input, artistic or social, I retreat to my studies. To wit:
The evolution of citrus probably began in the Malay Archipelago at least twenty million years ago, when the islands of the South Pacific were still part of a body of land that included Asia and Australia.
A bitter ancestral plant apparently made its way to what is now the Asian mainland, and from it developed the modern fruit. The evidence that this event occurred in the area of southern China is overwhelming, beginning with the fact that more citrus varieties and more citrus parasites can be found there than anywhere else.
Spreading out to the rest of the world, Chinese citrus jumped the East China Sea and reached Japan by way of Formosa and intervening island groups. It moved eastward into the South Pacific, and the frequency of citrus in the islands today diminishes with distance from the mainland.
In the junks of merchant seamen, seeds and trees were carried south to the shores of the Java Sea and into the Strait of Malacca, which was a kind of departure point for sometimes unexpected migrations to India and Africa on the strong westward currents of the Indian Ocean.
Among the first citrus varieties to make this journey —and then to go on into the Mediterranean basin— was the citron, which acquired its name because of an early confusion with another tree [the cedar and its cones].
The second-century writer Apuleius, for one, objected. He had been born in Africa and knew a cedar cone from an orange. In the eighteenth century, the Swedish botanist Carolus Linnaeus nonetheless made the name “citrus” official for the genus. So lemons, limes, citrons, oranges, grapefruit, and tangerines are now grouped under a name that means cedar.
McPhee, John (2011-04-01). Oranges (p. 63). Farrar, Straus and Giroux. Kindle Edition.