black rat snake vs Elaphe obsoleta

black rat snake and Elaphe obsoleta both are nouns.

Word	Noun	Adjective	Verb	Adverb
black rat snake	Yes	No	No	No
Elaphe obsoleta	Yes	No	No	No

As nouns, black rat snake and Elaphe obsoleta are synonyms defined as:

black rat snake and Elaphe obsoleta: large harmless shiny black North American snake

Other synonyms of black rat snake include blacksnake, mountain blacksnake, pilot blacksnake.

black rat snake (noun)	Elaphe obsoleta (noun)
large harmless shiny black North American snake	large harmless shiny black North American snake