You might think that the shape of the pineapple is so distinctive that it could not easily be mistaken for anything else. However, there are images on mural in the Roman ruined city of Pompeii and pottery models found in ancient Egyptians tombs that that have been interpreted by Thor Heyerdahl as pineapples, and as such as evidence of pre-Columbian transatlantic trade. Others remain to be convinced!
The distinctive shape of the pineapple has been employed as a symbol of decadent luxury since it was first introduced into Europe from South America in the sixteenth century. In 1661 Charles II was painted being presented with a rather odd looking imported fruit. The use of the pineapple as a status symbol by the aristocracy reached its height during the eighteenth and nineteenth centuries, when armies of gardening staff lovingly tendered pineapple plants within glasshouses, heated by coal fires or piles of rotting manure. Their task was to produce ever larger fruit to crown lavish tabletop displays of produce. National pride was at stake, in 1817 the British ambassador in Paris was able to humiliate the French by insisting that it was impossible to obtain respectable fruit for a banquet without sending his diplomatic coach to London. In July 1821 Lord Cawdaw’s gardener produced a massive ten pound eight ounce British grown fruit. In the United States it was possible to rent imported fruit for an evening’s function, only the extremely wealthy actually purchased a pineapple to eat. However all were overshadowed by the fourth Earl of Dunmore who erected a pineapple shaped folly which still stands on his estate in Stirlingshire.
The pineapple is an unusual member of a tropical family of plants called the Bromeliads in that it is ground dwelling. Almost all of the rest of the family are to be found growing perched high in the tops of trees in the tropical forests of South America. This strategy appears to evolve in dense forest, where insufficient light reaches ground level to sustain plant growth. The pineapple is also unusual in that it differs from most crops in the evolution of its sexual preferences. It differs from all its close relatives in being unable to fertilise itself. To produce seed a pineapple must have a partner since the plant has the ability to recognise its own pollen grains and prevent them from fertilising its own ovules. Typically during the domestication process of most crops individuals are selected which do not require partners other than themselves to ensure successful fruit production, because ‘self sufficient’ individuals tend to be more efficient at producing fruit. The pineapple is an exception to this rule because the cultivated fruit although potentially perfectly fertile will also develop in the absence of seed, indeed fruit containing seeds are undesirable. Thus by selecting plants which are unable to set seeds without a partner and by growing these in isolation or in blocks of genetically identical plants (by vegetative means) it ensures that only desirable seed-free fruit are produced.
In its native South America humming birds may pollinate the 100 to 200 flowers per pineapple, resulting in between 2000 and 3000, five millimetre long seeds being produced per fruit. Thus to protect the virginity of its pineapples and avoid unwanted seeds within its valuable commercial crop the U.S. state of Hawaii took the unusual step of outlawing all humming birds, declaring them undesirable aliens.
Although wild pineapples have been reported from several places including Brazil, Venezuela and Trinidad, it is considered that these populations are most likely the descendants of abandoned cultivated plants rather than being truly wild. The domestication of the pineapple pre-dates the arrival of the Europeans, but exactly where this occurred is uncertain. The first European contact with the fruit was on the Caribbean Island of Guadeloupe, where Columbus’ second voyage to the New World landed on the 4th November 1493. Although Columbus’ own log of the trip did not survive, crewmember Michele de Cuneo recorded finding fruit in the shape of a pinecone, but twice as big and excellent and wholesome. The same account goes on to describe another local delicacy in the form of two castrated boys that were being fattened for the pot. In the Caribbean pineapples are often eaten with a pinch of salt, and this may also be the best way of taking such stories of cannibalism which were often used to justify the barbaric treatment of the native people.
In 1874 in the Azores it was discovered that wood smoke could be used to induce flowering in pineapples. This enabled fruiting to be synchronised and thus improved the efficiency of harvesting. Later it was realised that it was ethylene in the smoke which was the active ingredient. Growers discovered that the same effect could be achieved by adopting the practice of putting calcium carbide (which reacts violently with water to produce acetylene which has the same effect on ripening) into the crown of each plant. However, too much carbide, a quick down pour and a spark, and bang your fruit may explode. Pineapple cultivation is not without other risks. The fruit contains bromelain, a mixture of protein digesting enzymes, which have been extracted as a meat tenderiser. These enzymes regularly digest away the fingertips of pineapple workers, but then that is a small price to pay for such a valuable status symbol.