Widespread European weed having yellow daisylike flowers; sometimes an obnoxious weed and toxic to cattle if consumed in quantity.

synonyms: benweed, ragwort, Senecio jacobaea, tansy ragwort.

Polish: starzec jakubek

Any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma.

synonyms: ambrosia, bitterweed.

Polish: ambrozja