red maple vs scarlet maple

red maple and scarlet maple both are nouns.

Word	Noun	Adjective	Verb	Adverb
red maple	Yes	No	No	No
scarlet maple	Yes	No	No	No

As nouns, red maple and scarlet maple are synonyms defined as:

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

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

red maple (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