What does "ripple-grass" mean?

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

Ripple-grass

Common synonyms include: buckthorn, english plantain, narrow-leaved plantain, plantago lanceolata, ribgrass, ribwort.

Rare ·Advanced level

Noun

1
an Old World plantain with long narrow ribbed leaves widely established in temperate regions wordnet