Sagina vs genus Sagina

Sagina and genus Sagina both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sagina	Yes	No	No	No
genus Sagina	Yes	No	No	No

As nouns, Sagina and genus Sagina are synonyms defined as:

Sagina and genus Sagina: small low-growing annual or perennial herbs of temperate and cool regions

Sagina (noun)	genus Sagina (noun)
small low-growing annual or perennial herbs of temperate and cool regions	small low-growing annual or perennial herbs of temperate and cool regions