mountain alder vs mountain maple

mountain alder and mountain maple both are nouns.

Word	Noun	Adjective	Verb	Adverb
mountain alder	Yes	No	No	No
mountain maple	Yes	No	No	No

As nouns, mountain alder and mountain maple are synonyms defined as:

mountain alder and mountain maple: small shrubby maple of eastern North America; scarlet in autumn

Other synonyms of mountain alder include Acer spicatum.

mountain alder (noun)	mountain maple (noun)
small shrubby maple of eastern North America; scarlet in autumn	small shrubby maple of eastern North America; scarlet in autumn
tree of western United States