creeping soft grass vs Holcus mollis

creeping soft grass and Holcus mollis both are nouns.

Word	Noun	Adjective	Verb	Adverb
creeping soft grass	Yes	No	No	No
Holcus mollis	Yes	No	No	No

As nouns, creeping soft grass and Holcus mollis are synonyms defined as:

creeping soft grass and Holcus mollis: European perennial grass with soft velvety foliage

creeping soft grass (noun)	Holcus mollis (noun)
European perennial grass with soft velvety foliage	European perennial grass with soft velvety foliage