mountain birch vs Betula fontinalis

mountain birch and Betula fontinalis both are nouns.

Word	Noun	Adjective	Verb	Adverb
mountain birch	Yes	No	No	No
Betula fontinalis	Yes	No	No	No

As nouns, mountain birch and Betula fontinalis are synonyms defined as:

mountain birch and Betula fontinalis: birch of western United States resembling the paper birch but having brownish bark

Other synonyms of mountain birch include swamp birch, water birch, Western birch, Western paper birch.

mountain birch (noun)	Betula fontinalis (noun)
birch of western United States resembling the paper birch but having brownish bark	birch of western United States resembling the paper birch but having brownish bark