A certain large country had a BIG birthday the other day. It’s a place that has had a huge influence on the rest of our planet, and in many ways.
I thought I might therefore make my article for this month on plants originating in the USA that we now grow in gardens here in Britain. There are, in fact, too many to include them all, but "here goes nuttin'", as they say over there..
Of fruits perhaps the best known are blueberries, which have become fashionably popular, not least as a good source of Vitamin C, and are closely related to the Eurasian bilberry (a much tarter tasting member of the same Vaccinium family), while of vegetables, we should be most grateful (in spite of its gas-producing tendencies) for the Jerusalem Artichoke (Helianthus tuberosus), the tubers of which make possibly the most wonderful soup in the world. It is a variety of perennial sunflower, native to what is now central and eastern USA, and barely related at all to the “European” artichoke, which is actually, and hardly surprisingly when you see its bristly blue flowers, a kind of thistle, originating from the Mediterranean areas of Europe and North Africa. “Jerusalem” is a corruption of the Italian girasole (sun-turner), a property it shares with all sunflowers, while “Artichoke” is derived from its Arabic name al-kharshuf. It was introduced from America by the explorer Samuel de Champlain, who brought the tuber to France in 1616. The plant rapidly became popular throughout Europe, not least because it grows well in cold and wet soil. A long time ago I tried growing it in a patch of pure Oxford clay (not in Eynsham): within three years six tubers had become six hundred, and systemic weedkiller was sadly the only means of preventing it from taking over half my garden.
I have not mentioned potatoes, tomatoes, nor maize (which our increasingly warm summers now make successful in many British plots), nor the squash family, which includes pumpkins. These are all native to “America”, but not the USA. Indigenous peoples in the Balsas River Valley area of south-central Mexico developed maize about 9,000 years ago, from an inedible native grass called teosinte, while squashes originated in a wider area of Mexico and Central America, and equally long ago, being bred from bitter gourds. Potatoes are first known of in an area further south, on the borders of Peru and Bolivia, and may well have also been grown there as long ago as 10,000 BC. Tomatoes are another member of the genus Solanum, and the wild tomato, originally a tiny, berry-like fruit, is native to a wide area of western South America, including parts of modern Peru, Ecuador, Bolivia, and Chile. The solanum family also brought us the now wildly popular chili pepper and the utterly deadly tobacco – all related to nightshades, like Solanum dulcamara, the Woody (or Bittersweet) Nightshade, and many are poisonous to humans. Though this is “merely” such plants’ defence against the danger of their being eaten by any animal, it can have unfortunate consequences for those who try. Potatoes are dangerous when unripe or green, and tomatoes (in their modern cultivated forms) are not perilous in the least, though it took them a long time to shake of that harmful reputation. Incidentally our native Deadly Nightshade, though indeed deadly, isn’t a “Solanum” at all, it just looks like one (plant taxonomy can be very complicated and confusing).
All of these American Solanums were discovered in situ by Spanish “conquistadors” and the like, and were introduced to Europe in the second half of the sixteenth century.
Flowers from the USA generally arrived somewhat later. The famous antiquarian and botanist John Tradescant mentions American asters, which we call Michaelmas Daisies, being grown in Britain in the 1630s, but their popularity really began in the eighteenth century and reached a peak in the Victorian era. There are over a hundred US native species of Aster (or Symphotrichum as many are now called, just to add to gardeners’ confusion), the most popularly-grown being varieties of Symphotrichum novae-angliae (“New England”) – there are over 70 to choose from. S. novi-belgii (“New Belgium”) has over 1,000 available forms, many still widely grown, though they like wetter soil and are horribly prone to mildew: I avoid them for that reason. In colour. Michaelmas daisies range from pure white through pink (pale and dark) to mauve-ish and deep purple, and their size can be anything from a few inches to over six feet. I recommend “Alma Potschke” (loud pink, 2’ 6), Maria Wolkonska (purple with a yellow centre, 3 feet), and “White Climax” (late flowering, white, 6 feet tall and spreads like mad).
Other flowers of US origin are the yellow-flowered Rudbeckias, always a cheerful sight in autumn: “Goldsturm”( 2-3feet) is a good reliable one, as tough as old boots, and there are excellent annual varieties as well. The same can be said for the children’s favourite Helianthus annuus, the annual sunflower, and perennial varieties of these can be stunning: “Lemon Queen” (pale yellow, six feet) is wonderful, flowering into November in mild weather. Coneflowers (Echinacea), a native of the US prairies, were always purple until recently, but breeders’ efforts have led to an explosion of varieties in every colour from white to almost black, via blazing reds, oranges and yellows, plus the two-tone green-purple form “Green Twister”, and there are also semi-doubles and “pom-pom” varieties. E. purpurea itself has long been used by indigenous Americans as a medicine for many ailments, and is a popular "alternative" remedy.
It is a perhaps an odd coincidence that so many of these introductions from the USA are members of that huge plant family, Compositae (daisies). On a totally unrelated topic, I notice that they lost the football … Had I been on time with this article I couldn’t have written that.