RAGWORT
butterweed, ragwort, Senecio glabellus
(noun) American ragwort with yellow flowers
ragwort, tansy ragwort, ragweed, benweed, Senecio jacobaea
(noun) widespread European weed having yellow daisylike flowers; sometimes an obnoxious weed and toxic to cattle if consumed in quantity
Source: WordNet® 3.1
Etymology
Noun
ragwort (countable and uncountable, plural ragworts)
Any of a number of wild flowering plants with yellow flowers in the family Asteraceae, mostly belonging to Senecio and related genera.
Source: Wiktionary
Rag"wort`, n. (Bot.)
Definition: A name given to several species of the composite genus Senecio.
Note: Senecio aureus is the golden ragwort of the United States: S.
elegans is the purple ragwort of South Africa.
Source: Webster’s Unabridged Dictionary 1913 Edition