From Longman Dictionary of Contemporary Englishragwortrag‧wort /ˈræɡwɜːt $ -wɜːrt/ noun [uncountable] HBPa common plant with yellow flowers, and leaves with uneven edges
Examples from the Corpus
ragwort• Nettles grew everywhere, and ragwort, and the wall itself was thick with plants growing in every available gap.• One stable owner at Evesham in Worcester is having to clear ragwort from his land by hand.• When he returned, every ragwort plant in the field sported a red banner.• Kali threw down her bunch of ragwort and it landed, splayed out limply, on the top.• One story is told of a man who saw a leprechaun bury a purse of gold in a field of ragwort. 