Crossword clue: a tall weed with purplish flowers (vernonia noveboracensis). the name is also applied to other plants of the same genus.
1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).
Possible answers
any of various plants of the genus Vernonia of tropical and warm regions of especially North America that take their nam