aspen vs poplar

aspen and poplar both are nouns.

Word	Noun	Adjective	Verb	Adverb
aspen	Yes	No	No	No
poplar	Yes	No	No	No

As nouns, poplar is a hypernym of aspen; that is, poplar is a word with a broader meaning than aspen:

aspen: any of several trees of the genus Populus having leaves on flattened stalks so that they flutter in the lightest wind
poplar: any of numerous trees of north temperate regions having light soft wood and flowers borne in catkins

Other hypernyms of aspen include poplar tree.

aspen (noun)	poplar (noun)
any of several trees of the genus Populus having leaves on flattened stalks so that they flutter in the lightest wind	any of numerous trees of north temperate regions having light soft wood and flowers borne in catkins
	soft light-colored non-durable wood of the poplar