At this time of year, the common ragwort, Senecio jacobaea, is in full bloom. Its golden brilliance is proverbial. As John Clare expressed it in 1831: "So bright and glaring that the very light / Of the rich sunshine cloth to paleness turn / And seems but very shadows in thy sight." And in 1948 Lady Vyvyan wrote of her experience in Cornwall: "In one small valley on the north coast of the county it pours down the cliff like a golden river. One may stand inland and gaze upon this mass of the lovely weed as it grows there triumphantly outlined on the blue sea."
Ragwort is the national flower of the Isle of Man, where it is called cushaq. In Ireland it is known as fairy horse, since it is the traditional mode of transport of fairies and witches. This idea of transport on the stalk of the ragwort was also current in Scotland, and was the subject of comments by Robert Burns. And Hamilton Davy in his 1909 Cornish flora mentions the same phenomenon: "It was at one time believed that the witches of West Cornwall were wont to gather on the steep cliffs near the Land's End and sail through the air to Wales on stalks of ragwort." In a more reputable connection, Senecio was known as St James's wort, possibly because on the feast day of that saint, July 25, it could be guaranteed to be in all its golden glory.
The other aspect of ragwort has stimulated a degree of hysteria among some members of the farming community which erupts every midsummer. In the dried state, if fed to cattle with hay and other fodder, it is poisonous, though much less so in the fresh state, and ponies which graze unwisely upon masses of it in meadows have died as a result.
The seed production of the plant is legendary, and it needs to be plucked up before its flowers mature if it has invaded fields where stock are grazed. In many situations it is effectively controlled by the caterpillars of the cinnabar moth, whose colour almost rivals that of their food plant, and is set off by their dark transverse stripes. The creatures strip ragwort back to its bare stems in no time, and are completely immune to the pyrrolizidine alkaloids which attack the liver, kidney and lung of higher animals. In recent years the cinnabar caterpillars seem not so flourishing as they used to be, if my memory is correct.