common grape vine vs Vitis

common grape vine and Vitis both are nouns.

Word	Noun	Adjective	Verb	Adverb
common grape vine	Yes	No	No	No
Vitis	Yes	No	No	No

common grape vine (noun)	Vitis (noun)
common European grape cultivated in many varieties; chief source of Old World wine and table grapes	the type genus of the family Vitaceae; woody vines with simple leaves and small flowers; includes a wide variety of grapes