Parrotia vs plant genus

Parrotia and plant genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Parrotia	Yes	No	No	No
plant genus	Yes	No	No	No

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

Parrotia (noun)	plant genus (noun)
one species: iron tree	a genus of plants