Humble weed has deadly effect
The favourite food plant of the striking yellow and black caterpillar of the cinnebar moth (tyria jacobacae), the common ragwort (bualachain or buachalan buidhe in Irish), has few admirers in the farming community, which generally regards it as a recurring pest and a control problem.
It may be seen on roadsides and within some small fields of neglect or abandonment, a yellow noxious weed that is regarded as a blight on the landscape.
At one time, farmers faced prosecution in the courts for failing to remove it -- by pulling by the roots to stop spreading then burning it on headlands. This does not appear to be a police matter any more, rather farmers' organisations are expected to exert some pressure on their members.
Extraordinarily, the plant was named for St James, the patron of horses and it was once believed that an infusion made from its leaves would cure head staggers -- a disease affecting the brain -- in the animals.
But in fact, the plant is a killer of horses as it contains an alkaloid poison, which remains when dried plants are dispersed in hay-making and mixed through bales that can be eaten unnoticed. The poison attacks the liver and within months can cause a painful death from cirrhosis.
Of grazing stock, sheep appear to be the only ones to escape as they carefully avoid it. Cattle can ingest the plant if it is distorted by herbicide. It is the cause of half of all animal stock poisoning.
Last Sunday, from a rural bus window, I saw a lone horse in a small roadside field blanketed in the yellow weed. This was certainly a surprise. An example of ignorance or carelessness, or, fingers crossed, a matter of temporary parking in a holding space? No matter, a convenience not to be recommended.
The golden ragwort is a rapid coloniser whose seeds disperse widely and in folklore it was considered a plant of the fairies and used by them as yellow horses to ride about the countryside. They also found shelter under the flowers where the legendary crock of gold might be buried! There is an old Sligo saying: "Don't call it a weed, though a weed it may be, it's the home of the fairies, the buhalan bui."
John Clare, the 19th century English country poet, was an admirer: "Ragwort, thou humble flower of tattered leaves/ I love to see thee come and litter gold."
One enterprising farmer in the north of England used to gather the plant and sell it in bunches to Sunday daytrippers from towns as "summer gold"! On the Isle of Man it is called "cushag " and is so widespread it is considered a national emblem.
One hundred years ago, a Dublin botanist Nathaniel Colgan (author of Flora of County Dublin, 1904) told of a hackney driver's cures for horse ailments using a mixture of 'he-bulkishawn' (ragwort) and 'she-bulkishawn' (common tansy, a tall perennial with yellow button flower heads). There were no details but tansy was known as a wormer and also an insecticide.
In Scotland, the descriptive, 'mare's fart', is an indication of its unpleasant effects on horses. How St James of Santiago de Campostela gained attribution by Linnaeus, the great naturalist (the plant's Latin name is senecio jacobaea) seems, in these times, misplaced to say the least.