St. Augustine grass vs genus Stenotaphrum

St. Augustine grass and genus Stenotaphrum both are nouns.

Word	Noun	Adjective	Verb	Adverb
St. Augustine grass	Yes	No	No	No
genus Stenotaphrum	Yes	No	No	No

St. Augustine grass (noun)	genus Stenotaphrum (noun)
low mat-forming grass of southern United States and tropical America; grown as a lawn grass	lawn grasses