nut grass vs Cyperus rotundus

nut grass and Cyperus rotundus both are nouns.

Word	Noun	Adjective	Verb	Adverb
nut grass	Yes	No	No	No
Cyperus rotundus	Yes	No	No	No

As nouns, nut grass and Cyperus rotundus are synonyms defined as:

nut grass and Cyperus rotundus: a widely distributed perennial sedge having small edible nutlike tubers

Other synonyms of nut grass include nut sedge, nutgrass, nutsedge.

nut grass (noun)	Cyperus rotundus (noun)
a widely distributed perennial sedge having small edible nutlike tubers	a widely distributed perennial sedge having small edible nutlike tubers