blue sage vs Salvia azurea

blue sage and Salvia azurea both are nouns.

Word	Noun	Adjective	Verb	Adverb
blue sage	Yes	No	No	No
Salvia azurea	Yes	No	No	No

As nouns, blue sage and Salvia azurea are synonyms defined as:

blue sage and Salvia azurea: blue-flowered sage of dry prairies of the eastern United States

blue sage (noun)	Salvia azurea (noun)
aromatic shrub of arid regions of western North America having hoary leaves	blue-flowered sage of dry prairies of the eastern United States
blue-flowered sage of dry prairies of the eastern United States
Texas sage having intensely blue flowers
sage of western North America to Central America having violet-blue flowers; widespread in cultivation