genus Vipera vs reptile genus

genus Vipera and reptile genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Vipera	Yes	No	No	No
reptile genus	Yes	No	No	No

As nouns, reptile genus is a hypernym of genus Vipera; that is, reptile genus is a word with a broader meaning than genus Vipera:

genus Vipera (noun)	reptile genus (noun)
type genus of the Viperidae	a genus of reptiles