In a few days' time the purple flowers will fade, and tufts of downy seed will travel far and wide on the wind to colonise new areas. The plants can be killed by spraying, but for organic farmers, who use no chemicals, they present a special problem as cutting does not kill them and they live for several years.
Thistles seem to have developed their sharp spikes as a form of protection. Most grazing animals will not tackle them when they are alive, but once they are dead, sheep, cattle and horses eat them with great relish.
The spikes also have the effect of eking out food supplies: in summer animals cannot get at the grass growing close round the plants; but they can reach it when the thistles have withered in autumn.
Arguments have raged for centuries about which species of thistle is represented by the emblem of Scotland. Some historians opt for Onopordum acanthium, the cotton thistle, others for Cirsium vulgare, the spear thistle, others again for Cirsium helenoides, the melancholy or drooping thistle. However, the central point is that the plant's prickly nature makes it an ideal symbol of defiance.Reuse content