swamp poplar vs downy poplar

swamp poplar and downy poplar both are nouns.

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

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

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

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

swamp poplar (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