Atlas Obscure:

Right from the moment of its discovery, the grapefruit has been a true oddball. Its journey started in a place where it didn’t belong, and ended up in a lab in a place where it doesn’t grow. Hell, even the name doesn’t make any sense.

THE CITRUS FAMILY OF FRUITS is native to the warmer and more humid parts of Asia. The current theory is that somewhere around five or six million years ago, one parent of all citrus varieties splintered into separate species, probably due to some change in climate. Three citrus fruits spread widely: the citron, the pomelo, and the mandarin. Several others scattered around Asia and the South Pacific, including the caviar-like Australian finger lime, but those three citrus species are by far the most important to our story.

With the exception of those weirdos like the finger lime, all other citrus fruits are derived from natural and, before long, artificial crossbreeding, and then crossbreeding the crossbreeds, and so on, of those three fruits. Mix certain pomelos and certain mandarins and you get a sour orange. Cross that sour orange with a citron and you get a lemon. It’s a little bit like blending and reblending primary colors. Grapefruit is a mix between the pomelo—a base fruit—and a sweet orange, which itself is a hybrid of pomelo and mandarin.

Because those base fruits are all native to Asia, the vast majority of hybrid citrus fruits are also from Asia. Grapefruit, however, is not. In fact, the grapefruit was first found a world away, in Barbados, probably in the mid-1600s. The early days of the grapefruit are plagued by mystery. Citrus trees had been planted casually by Europeans all over the West Indies, with hybrids springing up all over the place, and very little documentation of who planted what, and which mixed with which. Citrus, see, naturally hybridizes when two varieties are planted near each other. Careful growers, even back in the 1600s, used tactics like spacing and grafting (in which part of one tree is attached to the rootstock of another) to avoid hybridizing. In the West Indies, at the time, nobody bothered. They just planted stuff.

Sometimes it didn’t work very well. Many citrus varieties, due to being excessively inbred, don’t even create a fruiting tree when grown from seed. But other times, random chance could result in something special. The grapefruit is, probably, one of these. The word “probably” is warranted there, because none of the history of the grapefruit is especially clear. Part of the problem is that the word “grapefruit” wasn’t even recorded, at least not in any surviving documents, until the 1830s.

Before that it was known, probably, as the “shaddock,” which is especially confusing, because shaddock is also a word used for the pomelo. (The word may have come from the name of a trader, one Captain Philip Chaddock, who may or may not have introduced the pomelo to the islands.) As a larger, more acidic citrus fruit with an especially thick rind, the pomelo is what provides the bitterness for all bitter citrus fruits to follow, including the grapefruit. In the earliest and best history of the fruits on Barbados, written by Griffith Hughes in 1750, there are descriptions of many of the unusual hybrids that littered Barbados. Those trees include the shaddock, a tree he called the “golden orange,” and one he called the “Forbidden Fruit” tree. It was the latter that Hughes described as the most delicious, and when the grapefruit eventually became easily the most famous and popular citrus of the West Indies, it was widely believed to be the one once called the Forbidden Fruit.

It turns out this may have just been wishful thinking. Some truly obsessive researchers spent years scouring the limited, centuries-old descriptions of citrus leaf shapes and fruit colors, and concluded that of those three interestingly named fruits, the shaddock was the pomelo, the golden orange was actually the grapefruit, and the Forbidden Fruit was actually something else entirely, some other cross, which the researchers think they may have found on Saint Lucia, back in 1990.

Speaking of all these names, let’s discuss the word “grapefruit.” It’s commonly stated that the word comes from the fact that grapefruits grow in bunches, like grapes. There’s a pretty decent chance that this isn’t true. In 1664, a Dutch physician named Wouter Schouden visited Barbados and described the citrus he sampled there as “tasting like unripe grapes.” In 1814, John Lunan, a British plantation and slave owner from Jamaica, reported that this fruit was named “on account of its resemblance in flavour to the grape.”

If you’re thinking that the grapefruit doesn’t taste anything like grapes, you’re not wrong. It’s also documented that there were no vine grapes in Barbados by 1698. That means, according to one theory, that many of the people on the island would not really have known what grapes tasted like. Their only native grape-like plant is the sea grape, which grows in great numbers all around the Caribbean, but isn’t a grape at all. It’s in the buckwheat family, but does produce clusters of fruit that look an awful lot like grapes but aren’t particularly tasty. In fact, they’re quite sour and a little bitter, not unlike the grapefruit.

And, just wait until you read about its interaction with drugs! RTWT