Elaphe obsoleta vs black rat snake

Elaphe obsoleta and black rat snake both are nouns.

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

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

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

Other synonyms of Elaphe obsoleta include blacksnake, mountain blacksnake, pilot blacksnake.

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