Acer rubrum vs scarlet maple

Acer rubrum and scarlet maple both are nouns.

Word	Noun	Adjective	Verb	Adverb
Acer rubrum	Yes	No	No	No
scarlet maple	Yes	No	No	No

As nouns, Acer rubrum and scarlet maple are synonyms defined as:

Acer rubrum and scarlet maple: maple of eastern and central America; five-lobed leaves turn scarlet and yellow in autumn

Other synonyms of Acer rubrum include red maple, swamp maple.

Acer rubrum (noun)	scarlet maple (noun)
maple of eastern and central America; five-lobed leaves turn scarlet and yellow in autumn	maple of eastern and central America; five-lobed leaves turn scarlet and yellow in autumn