smut grass vs blackseed

smut grass and blackseed both are nouns.

Word	Noun	Adjective	Verb	Adverb
smut grass	Yes	No	No	No
blackseed	Yes	No	No	No

As nouns, smut grass and blackseed are synonyms defined as:

smut grass and blackseed: grass native to West Indies but common in southern United States having tufted wiry stems often infested with a dark fungus

Other synonyms of smut grass include carpet grass, Sporobolus poiretii.

smut grass (noun)	blackseed (noun)
grass native to West Indies but common in southern United States having tufted wiry stems often infested with a dark fungus	grass native to West Indies but common in southern United States having tufted wiry stems often infested with a dark fungus