common tobacco vs Nicotiana tabacum

common tobacco and Nicotiana tabacum both are nouns.

Word	Noun	Adjective	Verb	Adverb
common tobacco	Yes	No	No	No
Nicotiana tabacum	Yes	No	No	No

As nouns, common tobacco and Nicotiana tabacum are synonyms defined as:

common tobacco and Nicotiana tabacum: tall erect South American herb with large ovate leaves and terminal clusters of tubular white or pink flowers; cultivated for its leaves

common tobacco (noun)	Nicotiana tabacum (noun)
tall erect South American herb with large ovate leaves and terminal clusters of tubular white or pink flowers; cultivated for its leaves	tall erect South American herb with large ovate leaves and terminal clusters of tubular white or pink flowers; cultivated for its leaves