As we tuck into the vegetables alongside our Sunday roast (or maybe devour a delicious plate of roasted ditto, should we not be meat-eaters), very few of us, probably, think even for a moment of what exactly we’re eating, nor whence it comes. I’m not thinking of out-of-season asparagus being flown in from South America, but what about: “Why are carrots orange”, or “What exactly IS broccoli”?
The latter first: I was very surprised to learn a while ago that broccoli, like cauliflower, purple sprouting, savoy cabbage, white cabbage, the oh-so-fashionable kale, and the “dreaded” Brussel sprouts, are all derived from the original wild cabbage, Brassica oleracea, found growing on the coasts of Britain, France, Italy, and Spain. It is closely related to Brassica cretica, a plant of the eastern Mediterranean, and several other similar species. All are notably “acephalic”, that is, they have no dense central “head”. B. oleracea and cretica both make a rosette of leaves, which in its second year sends up a woody spike up to 1.5 metres (5ft) tall, from which branch long stems of small flowers. These are yellow and four-petalled – hence the plant's family name of “Cruciferae” (cross-bearing); one of their close floral relatives is Night-scented Stock. Their thick and fleshy leaves help them survive in their salt-laden native environment and aid the storage of water. Broccoli, sprouts, purple sprouting and cauliflower all come from various selections of these branches of flowers, savoy and other cabbage forms from breeding tighter and thicker leaf masses, while the sadly-neglected-but-delicious kohlrabi was selectively derived from wild forms with thick and fleshy stems (its name is from the German for "cabbage" and "turnip" - quite obvious when you see one).
Incidentally, lettuce (Lactuca sativa), in spite of its superficially similar appearance, does not enter into this picture at all. It’s a member of a totally different family, Compositae, and is not that distantly related to Michaelmas daisies, chrysanthemums … and chicory. Like the cabbages, the lettuce family can taste bitter. This is a case of convergent evolution intended to put off would -e grazing animals that preferred something sweeter, or at least less sour. It certainly continues to dissuade many human animals from eating their greens, particularly, for some unknown reason, men.
A carrot in flower might itself look a little like a lettuce in flower, but this is again a happenstance of evolution, producing two similar-looking mechanisms for the dispersal of seeds in plants belonging to different botanical families. Carrot, ”Daucus carota” in Latin, is a species from the huge family Apiaceae, which includes many familiar herbs, including fennel, parsley, coriander, lovage, dill, and cumin, as well as celery and parsnip. It also has some nasty wild relatives, such as Giant Hogweed and the deadly poisonous hemlock (used to murder under law the great Athenian philosopher Socrates).
Why is the carrot orange? The simple answer is that it doesn’t need to be. . Though most carrots are orange, there are also yellow, white, purple, red and black varieties available., and we have all seen such “heritage carrots” in shops in recent years - a clever retail wheeze to tempt the consumer to pay rather more for some supposedly historic variety, while making us feel warm and fuzzy about encouraging the said heritage.
The predominance of the orange form may date from the 16th century Netherlands, relating to the House of Orange-Nassau, whose famous leader William the Silent led the Dutch Revolt against their Spanish overlords, beginning in the 1560s (his descendants are still the reigning family in that country). At that time, most carrots in Britain were white, and no name differentiation was made between them and parsnips. “Carroty” as a colour name in English is first recorded by the Oxford English Dictionary in 1685, and in reference to hair, as it still is today. However, the word “carrot” has nothing to do with colour at all: it derives ultimately from the proto-Indo-European root “-ker”, meaning “horn”, because of its shape.
Chemically, the characteristic orange colour of this vegetable derives from beta-carotene, which makes carrots an excellent source of vitamin A. The belief that carrots help people to see in the dark originated in World War II propaganda, to account for the ability of British pilots to fight at night. The real explanation was the far more mundane, though amazingly effective, introduction of radar. The carrot stores sugar in its taproot, and the higher the quality of the variety the higher the proportion of the pulpy outer cortex (phloem) to the inner core (xylem), When carrots get big the outer pulp can be both watery and bland, while the core resembles a chair leg in both texture and taste - it is little wonder that “baby carrots”, which have almost no core, sell at a premium.
Carrots and cabbage are both excellent examples of how far cultivation has altered the wild antecedent. The latter has branched out into many man-made forms, and there are over 500 varieties of carrot in cultivation. It is Britain’s most-grown vegetable, annual production totalling over 650,000 tons grown in over 22,000 acres of fields. Statistics, history, taste, and colour to one side, the humble carrot has another remarkable characteristic: if allowed to live into its second year, it not only blooms (on stalks over six feet high), but those tiny flowers change sex.