Crossword clue: an old world plantain with long narrow ribbed leaves widely established in temperate regions

The most common answer is buckthorn (9 letters).

3 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

buckthorn 9 letters wn-def

an Old World plantain with long narrow ribbed leaves widely established in temperate regions

ribgrass 8 letters wn-def

an Old World plantain with long narrow ribbed leaves widely established in temperate regions

ribwort 7 letters wn-def

an Old World plantain with long narrow ribbed leaves widely established in temperate regions