This familiar native plant, with its all yellow flowers from June, is a valuable food plant for bees, pollinating insects and lepidopterans, especially the orange and black striped caterpillars of the Cinnabar Moth.
Conversely, livestock know about Common Ragwort, and how it is poisonous in the field; they can smell it, and will give it a wide berth. However, if the plant is cut and left to dry so that it no longer gives off its distinctive smell, is then mixed with other grasses and bundled into winter hay, it has the ability to kill any unsuspecting livestock that eat it.
There's a detailed discussion on the Knepp Wildland Podcast about Common Ragwort (episode 39, The Plant People Love to Hate) with Isabella Tree and Mick Crawley, Emeritus Professor of Plant Ecology at Imperial College London. The extraordinary value of the plant to wildlife is examined, as is the unintended consequence of trying to eradicate the plant.
Witches and faeries travel on ragwort stalks. Ragwort is astringent, and also makes an emollient poultice for burns, sores, ulcers and inflamed joints.
This plant food is favoured by Red-tailed Bumblebees.
[As with most plants whose names end with the suffix 'wort' (from the Old English wyrt, meaning 'plant'), the first part of the word often indicated a medical or physical complaint—or part of the body—for which the use of the plant in some manner was supposed to be effective. In this instance, Ragwort's name came from its ragged appearance. As a poisonous plant—at least for livestock, the plant had no medical uses other than its external use in making poultice.]
