It’s hard to talk about Ragwort without getting in to trouble with someone. A bit like aspartame really. There is the issue of Ragwort being poisonous if eaten by horses, a bit like Rhododendrons or Buttercups. Both Buttercups and Ragwort taste pretty vile while they are green and growing. Buttercups loose their taste and toxicity when they are mown, dried and made into hay. Unfortunately, Ragwort looses its scent and taste but not its toxicity, so a horse who would normally avoid Ragwort in the paddock or meadow, is quite likely to eat it in the stable. The Ragwort toxins damage the liver, so for maximum effect the horse needs to either, eat a couple of kilos of the stuff at one sitting, or smaller amounts every day over a longer period. The odd mouthful, like the occasional slice of Rhubarb Crumble, doesn’t do much damage.
Then, there is the Cinnabar Moth and the eight or nine other moths, butterflies and beetles who exists only if the Ragwort exists. As the incidence of Ragwort is declining currently, so are the populations of these Ragwort dependant species. Moreover, there are around a hundred and twenty other insects for whom Ragwort is an important part of their life cycle.
The really irritating thing about insects of course is, that they are at the bottom of the food chain for many other insects, birds and animals.
As with so many plants, if you take Ragwort away, the whole inverted pyramid comes tumbling down and we loose a big chunk of our wildlife.