Flowering head of Daucus carota, by Joaquim Alves Gasper.
PLANT LIFE
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The carrots changed their colours while coming in from the wild. well bred carrot Tom Kennedy describes how
were indeed the varieties that were first to go into cultivation. The purple rooted carrot appears to have spread to the adjoining countries during the 10th century, and by the 14th century cultivation had reached the Mediterranean. At that point, breeders managed to make the transfomation from purple to orange, and we know this from the writings of a 12th century Spanish Moslem scholar and agriculturalist, ibn al-‘Awwam, author of a 34 chapter book describing over 600 different plants and fruit trees. From there, orange carrots went to the lowlands, and no doubt the rise of the House of Orange is the reason they became so popular in The Netherlands during the 17th century. From there, the orange carrot crossed over to England, where, the gentleman scholar, John Aubrey noted their arrival in Somersetshire. Both forms, and their derivatives, are now among the world’s major crops, with something like 25 million tonnes being grown every year. Far from being grateful to the ancestor, growers are not too happy to allow wild carrots steal into their fields, and in the US, Daucus carota is classed officially as a noxious weed. By nature, the flowering top of a carrot is popular with pollinating insects, and apart from liking to mix and mingle, the wild form might be a bit of an uncivilised hillbilly, but it is genetically superior.
t can be hard to sort out the umbrella plants, and at first glance all those flowering heads look a bit the same, but only in the way that all “black” birds, whether rook, cawing crow or sweetly singing blackbird, can look alike. There are a lot of umbrella plants, and it would be a bad mistake to mix up the hogweed or millfoil with the poisonous hemlock. However, there is usually a well defined and easily identifiable clue that helps with identification, and with the wild carrot, it’s the cage. The ancestor of all those orange carrots is among our common wild plants, and at this time of the year it is fairly easy to spot because the umbrella of white flowers closes up into a distinctive cage-like head. Although it is the right species, the roots of this particular Daucus carota bear little resemblance to the carrot in the shops. Stringy, pale and going tough with age, the root of the wild carrot can be eaten, and perhaps this is why breeders decided to improv e on nature. It is thought that selection and cultivation began about two thousand years ago in Afghanistan. During the Soviet occupation, botanists who scoured the country for seeds, found that the diversity was unusually high, particularly for purple carrots, and these
The flowering head of wild Daucus carota, with deeply cut leaves, and close up of the seed, with cross section shown on the lower left.
SCIENCE SPIN Issue 48 Page 35