blue devil vs viper's bugloss

blue devil and viper's bugloss both are nouns.

Word	Noun	Adjective	Verb	Adverb
blue devil	Yes	No	No	No
viper's bugloss	Yes	No	No	No

As nouns, blue devil and viper's bugloss are synonyms defined as:

blue devil and viper's bugloss: a coarse prickly European weed with spikes of blue flowers; naturalized in United States

Other synonyms of blue devil include blue thistle, blueweed, Echium vulgare.

blue devil (noun)	viper's bugloss (noun)
the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic	a coarse prickly European weed with spikes of blue flowers; naturalized in United States
a coarse prickly European weed with spikes of blue flowers; naturalized in United States