Agropyron repens vs couch grass

Agropyron repens and couch grass both are nouns.

Word	Noun	Adjective	Verb	Adverb
Agropyron repens	Yes	No	No	No
couch grass	Yes	No	No	No

As nouns, Agropyron repens and couch grass are synonyms defined as:

Agropyron repens and couch grass: European grass spreading rapidly by creeping rhizomes; naturalized in North America as a weed

Other synonyms of Agropyron repens include dog grass, quack grass, quackgrass, quick grass, witch grass, witchgrass.

Agropyron repens (noun)	couch grass (noun)
European grass spreading rapidly by creeping rhizomes; naturalized in North America as a weed	European grass spreading rapidly by creeping rhizomes; naturalized in North America as a weed