QI: The Book of General Ignorance - the Noticeably Stouter Edition (42 page)

There is no such thing as a banana tree.

The banana plant is actually a giant herb and the bananas are its berries.

A herb is defined as ‘a plant with a fleshy not a woody stem, which, after the plant has bloomed and set seed, dies down to the ground’. This is not always true: sage, thyme and rosemary have woody stems (though they are not covered with true bark).

As the definition says, after flowering, the part of the herb above the ground dies. With bananas, this gives rises to a strange effect. After the stem dies, another one grows, slightly further along the root. Over a few years, the banana plant will appear to have ‘walked’ a couple of yards.

Bananas are native to Malaya and have been cultivated for 10,000 years. Wild bananas, which can still be found in South-East Asia, contain large stony seeds and a small amount of flesh. They are pollinated by bats.

The banana in your local supermarket is a cultivated variety, chosen by farmers for its fleshy pulp and lack of seeds. Domestication has produced plants that are sweet and tasty but sterile: they cannot reproduce without human help.

Most banana plants have not had sex for 10,000 years.
Almost every banana we eat has been propagated by hand, from a sucker of an existing plant, whose genetic material has not changed in 100 centuries.

As a result, bananas are extremely susceptible to disease. Many species have already succumbed to fungal infections like black Sigatoka and Panama disease, which are impervious to fungicides. Unless a genetically modified version can be developed soon, all bananas may become extinct.

This is a serious problem. Bananas are the most profitable export crop in the world. The industry is worth $12 billion a year and supports 400 million people, many of them living well below the poverty line.

Most bananas come from hot countries, but Europe’s largest producer is Iceland. The bananas are grown in large greenhouses heated by geothermal water, just two degrees below the Arctic Circle.

Fyffe’s, the banana multinational that buys the entire crop of Belize each year, is Irish.

Coffee seeds, not beans.

Coffee is really a fruit. What we call coffee ‘beans’ are, botanically speaking, seeds. Coffee trees produce delicate white, jasmine-like blossom which lasts only a few days. The flowers give way to fruit called ‘coffee cherries’ which turn bright red when ripe. The skin of the cherry is bitter but the flesh is intensely sweet with a grape-like texture. Inside various further layers are two bluish-green seeds.

The word bean once meant only the seed of the broad bean. This later expanded to include members of the
Phaseolus
family such as the haricot bean and the runner bean, and the related genus Vigna which includes mung and adzuki beans and black-eyed peas. The term is now applied to other related plants such as soybeans, peas, lentils, vetches and lupins.

The coffee tree is an evergreen which grows 20 feet tall but is pruned to 8 to 10 feet. Coffee pickers can pick 100 to 200 lb of coffee cherries per day. Only 20 per cent of this weight is the actual seed. It takes about 2,000 Arabica cherries to produce a pound of roasted coffee. Since each cherry contains two beans, your one pound of coffee is derived from 4,000 coffee ‘beans’. In 5 to 10 per cent of any coffee crop, the cherry will contain only a single seed. This is called a ‘peaberry’ and it has a distinctly different, stronger flavour than normal.

In common English usage, the word ‘beans’ also refers to seeds or other organs of other plants. For example: castor beans (from which castor oil is made); cocoa beans (which resemble bean seeds), and vanilla beans (which resemble the pods). Botanically, none of these is a bean either.

A berry is defined as ‘a fleshy fruit containing several seeds’.

Strictly speaking, strawberries, raspberries and blackberries are not berries but ‘aggregated drupes’ – a drupe being a fleshy fruit containing a single stone or pit.

Peaches, plums, nectarines and olives are drupes. The world’s largest drupe is the coconut, which, because of its hard flesh, is called a ‘dry drupe’.

Strawberries, raspberries and blackberries are called ‘aggregated’ drupes because each individual fruit is actually a cluster of miniature drupes – the characteristic bumply bits which make up blackberries and raspberries.

Each one of these drupelets contains a single tiny seed – these are the bits that get stuck in your teeth when you eat a blackberry.

Tomatoes, oranges, lemons, grapefruit, watermelons, kiwi fruit, cucumbers, grapes, passion fruit, papaya, peppers and bananas are all berries.

Blueberries are also berries. They are variously known as bleaberries, bilberries, whortleberries, huckleberries, hurtleberries, myrtleberries and trackleberries.

Nuts are defined as a simple, dry fruit with one seed (very occasionally two) in which the seed-case wall becomes very hard at maturity.

True nuts include walnuts, butternuts, hickory, pecan, chestnut (but not conkers), beech, oak acorns, tan oak, hazel, filbert, hornbeam, birch and alder.

Peanuts, almonds, pistachios, Brazils, cashews, coconuts, horse chestnuts and pine nuts are not nuts. So the legendary health warning on a packet of peanuts (‘may contain nuts’) is, strictly speaking, untrue.

Brazil nuts are not nuts but seeds. The wooden pods they come in (up to twenty-four to a pod) grow right at the top of the tree, 45 metres (150 feet) above the ground, and are lethal if they fall on you. In Brazil, the pods are called
ouricos
, ‘hedgehogs’.

Almonds are the stone of a once fleshy drupe.

Peanuts, also known as groundnuts, earthnuts, goobers, goober peas, pindas, pinders, Manila nuts and monkey nuts, are actually a type of pea which grows underground.

They are native to South America but now widely cultivated, notably in Georgia, USA. Some people are so severely allergic to peanuts that eating a tiny amount (or even inhaling peanut dust) can be fatal; these people may or may not also be allergic to true nuts.

Pistachios are deadly dangerous. They are classified under Class 4.2. of the International Maritime Dangerous Goods code: Flammable Solids (Substances Liable To Spontaneous
Combustion). Fresh pistachios, if stacked under pressure, can burst into flames and cause a cargo fire.

Pistachios continue to absorb oxygen and excrete carbon dioxide even after harvesting. This can be a serious problem when transporting them by sea. If there is inadequate ventilation, seamen entering the hold of a cargo ship can die from carbon dioxide poisoning or from lack of oxygen.

Pistachios have been eaten by humans for at least 9,000 years. According to Muslim legend, the pistachio was one of the foods brought to Earth by Adam when he came down from Heaven.

No one. There are no nuts to gather in May. The children’s song is a corruption of the phrase ‘Here we go gathering knots of may’. It refers to the ancient custom of picking bunches (knots) of flowers on May Day to celebrate the end of winter, or ‘to go a-maying’.

May, the blossom of the hawthorn, is the only British flower to be named after the month in which it blooms. The may-tree is the origin of both the maypole and the phrase ‘Ne’er cast a clout before May is out’ – which refers not to the ending of the month, but to the opening of the flowers.

Though the may-tree is closely associated with May Day, it blossoms in the middle of the month not at the beginning of it. This is due to the change to the Gregorian calendar in 1752. Before this, May Day would have occurred eleven days later, exactly the time when the may-tree breaks into flower.

It is considered extremely unlucky to bring hawthorn flowers inside the house, a superstition more widely believed for may than for any other species of plant in the British Isles.

There are many possible reasons for this but the most convincing is to do with its smell. Hawthorn flowers have a heavy, complicated scent, the distinctive element of which is triethylamine, which is also one of the first chemicals produced by a dead human body when it starts to decay.

In some areas it is still referred to as ‘the smell of the Great Plague’ and people who know say it reminds them of the smell of gangrene. In the old days, bodies were laid out at home for up to a week before burial, and everybody would have been familiar with the smell of death. Hawthorn brought inside the house would have instantly triggered the association.

On the other hand, triethylamine is also the smell of sex: specifically of semen; hence its positive association with wild springtime rogering
outside
in the fields.

As well as ‘may’, hawthorn is also known as usual by scads of bizarre vernacular names including ‘bread-and-cheese’, ‘arzy-garzies’ and ‘aglets’. ‘Aglet’ is also the word for the little metal or plastic tip on the end of a shoelace.

Not milk, but coconut water. Coconut milk has to be made by boiling the white coconut ‘meat’ with water and straining it. Boil this down further and you get coconut cream.

Coconut is the only plant to produce such a seed liquid. As the coconut grows, the seed inside changes into a sweet, spongy mass called the ‘coconut apple’. From this the young plant shoot emerges out of one of the three holes at the end.

Fresh coconut water is an excellent hangover cure. It is completely sterile, full of vitamins and minerals and has the same balance of salts as human blood (the technical term for this is isotonic).

Because of this it can be used in place of a saline drip and is being commercially exploited as a sports drink, particularly in Brazil, where it is now a $75-million industry. Coconut water also ferments quickly and can be made into wine or vinegar.

Coconut oil is used to treat AIDS. Far from being the world’s most dangerously fatty oil, it is now being marketed as the healthiest. It is rich in lauric acid, the saturated fat found in mother’s milk, and full of anti-viral and anti-bacterial properties. It’s also been shown to reduce cholesterol, as it doesn’t enter the bloodstream but travels straight to the liver.

Some less well known uses for the coconut palm: DaimlerChrysler now use the husk (or coir) to make biodegradable seats for their trucks (springier than plastic foam); the root is liquefied to make mouthwash and a flour made from the shell is used to clean jet engines. The first car body to be made of coconut is already on the drawing board.

The coconut palm has been heralded as the world’s most useful tree for more than 3,000 years. In early Sanskrit texts it was referred to as
kalpa vriksha
– the tree that fulfils all needs.

You could survive on a desert island by eating and drinking only coconut.