Ragwort?

From wikipedia http://en.wikipedia.org/wiki/Jacobaea_vulgaris#Poisonous_effects: 'Ragwort contains many different alkaloids, making it poisonous to certain animals', 'Ragwort is of concern to people who keep horses and cattle', 'Horses do not normally eat fresh ragwort due to its bitter taste. It loses this taste when dried and can become a danger in hay.', the article also mentions that ragwort is theoretically poisonous to humans but is not a desirable food since it's so bitter tasting. Seperately, people sensitive to 'sesquiterpine lactones' can have an allergic reaction to the plant. Honey produced by bees feeding on ragwort contains certain harmful substances but the quantity of the substances in the honey is minute and so of no concern. medical uses: 'From medieval times to the mid 20th century, Ragwort was used against inflammations of the eye, for sore and cancerous ulcers, rheumatism, sciatica and gout, for painful joints. According to some, it would relieve the pain of bee stings. Any applications are external only, never taken internally, and only under professional supervision.' The plants leaves can also be used to obtain a 'good green dye' , yellow dye can be obtained from the flowers, as can orange and brown: http://en.wikipedia.org/wiki/Jacobaea_vulgaris#Other_usage