swamp cottonwood vs downy poplar

swamp cottonwood and downy poplar both are nouns.

Word	Noun	Adjective	Verb	Adverb
swamp cottonwood	Yes	No	No	No
downy poplar	Yes	No	No	No

As nouns, swamp cottonwood and downy poplar are synonyms defined as:

swamp cottonwood and downy poplar: North American poplar with large rounded scalloped leaves and brownish bark and wood

Other synonyms of swamp cottonwood include black cottonwood, Populus heterophylla, swamp poplar.

swamp cottonwood (noun)	downy poplar (noun)
North American poplar with large rounded scalloped leaves and brownish bark and wood	North American poplar with large rounded scalloped leaves and brownish bark and wood