Six vegetables from one wild plant
Wild cabbage is a scrappy plant that grows on sea cliffs around the coasts of Europe. Over the centuries farmers picked out plants with the features they liked best and bred from them, and it turned into a whole shelf of the vegetable aisle. Choosing big leaves gave KALE. A tight ball of leaves at the top became CABBAGE. Fat clusters of flower buds became BROCCOLI and, whiter and denser, CAULIFLOWER. Brussels sprouts are the buds along the side of the stem.
All of them are still the same species, and they share a taste some people love and others cannot stand. A bitter-tasting chemical in them is more noticeable to people with a particular version of one taste gene.
Vegetable is a kitchen word
Botanists do not use the word vegetable at all. To them, a CUCUMBER, a PEPPER, a PUMPKIN, an EGGPLANT and a ZUCCHINI are fruits, because they grow from flowers and hold seeds. So are PEAS and CORN. A CARROT, a RADISH and a BEETROOT are roots. ASPARAGUS is a young shoot, and the part of CELERY you eat is the leaf stalk. An ONION, GARLIC and a LEEK are layers of leaf bases, SPINACH and LETTUCE are leaves, and a POTATO is a swollen underground stem. A MUSHROOM is not a plant at all but a fungus.
Cooks sort things by taste instead: savoury goes in the main course. In 1893 the United States Supreme Court even ruled that tomatoes counted as vegetables for import taxes, because that is how people eat them. Our gardening page covers the botany of the TOMATO. Americans say ZUCCHINI and EGGPLANT where the British say courgette and aubergine; the first eggplants to reach Europe were small, white and shaped like eggs.
The potato that changed Europe
Potatoes were first grown in the Andes of South America around 7,000 years ago, and our Incas page covers the empire that farmed hundreds of kinds. Spanish ships brought them to Europe in the late 1500s, where many people distrusted a plant that grew underground. In France, the pharmacist Antoine-Augustin Parmentier, who had lived on potatoes as a prisoner of war, campaigned for them. The story goes that he had a potato field guarded by day and left unguarded at night, so that curious neighbours would steal the crop and plant it.
By the 1840s about a third of the people of Ireland depended almost entirely on potatoes. When a plant disease called blight destroyed the crop from 1845, around a million people died in the Great Famine and more than a million emigrated.
Tears, smells and a myth about iron
Cutting an ONION breaks open its cells and releases a chemical that turns into a stinging gas, and your eyes water to wash it away. Chilling the onion first slows the reaction. ASPARAGUS makes most people's wee smell, but many people cannot smell it, depending on their genes. BEETROOT turns some people's wee pink.
SPINACH is famous for iron thanks to the cartoon sailor Popeye, but it has no more than many other greens, and the iron is hard for the body to absorb. A popular story blames a misplaced decimal point in an old study for the myth. Historians have found no evidence for that error either, so the story about the myth is a myth too.