nutgrass vs nut grass

nutgrass and nut grass both are nouns.

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

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

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

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

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