nut grass vs nutgrass

nut grass and nutgrass both are nouns.

Word	Noun	Adjective	Verb	Adverb
nut grass	Yes	No	No	No
nutgrass	Yes	No	No	No

As nouns, nut grass and nutgrass are synonyms defined as:

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

Other synonyms of nut grass include Cyperus rotundus, nut sedge, nutsedge.

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