Rubia vs genus Rubia

Rubia and genus Rubia both are nouns.

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

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

Rubia and genus Rubia: type genus of the Rubiaceae; Old World herbs and subshrubs grown for their medicinal properties and for dye substances extracted from their roots

Rubia (noun)	genus Rubia (noun)
type genus of the Rubiaceae; Old World herbs and subshrubs grown for their medicinal properties and for dye substances extracted from their roots	type genus of the Rubiaceae; Old World herbs and subshrubs grown for their medicinal properties and for dye substances extracted from their roots