butterbur vs bog rhubarb

butterbur and bog rhubarb both are nouns.

Word	Noun	Adjective	Verb	Adverb
butterbur	Yes	No	No	No
bog rhubarb	Yes	No	No	No

As nouns, butterbur and bog rhubarb are synonyms defined as:

butterbur and bog rhubarb: small Eurasian herb having broad leaves and lilac-pink rayless flowers; found in moist areas

Other synonyms of butterbur include Petasites hybridus, Petasites vulgaris.

butterbur (noun)	bog rhubarb (noun)
small Eurasian herb having broad leaves and lilac-pink rayless flowers; found in moist areas	small Eurasian herb having broad leaves and lilac-pink rayless flowers; found in moist areas