grey poplar vs gray poplar

grey poplar and gray poplar both are nouns.

Word	Noun	Adjective	Verb	Adverb
grey poplar	Yes	No	No	No
gray poplar	Yes	No	No	No

As nouns, grey poplar and gray poplar are synonyms defined as:

grey poplar and gray poplar: large rapidly growing poplar with faintly lobed dentate leaves grey on the lower surface; native to Europe but introduced and naturalized elsewhere

Other synonyms of grey poplar include Populus canescens.

grey poplar (noun)	gray poplar (noun)
large rapidly growing poplar with faintly lobed dentate leaves grey on the lower surface; native to Europe but introduced and naturalized elsewhere	large rapidly growing poplar with faintly lobed dentate leaves grey on the lower surface; native to Europe but introduced and naturalized elsewhere