Centaurea cineraria vs centaury

Centaurea cineraria and centaury both are nouns.

Word	Noun	Adjective	Verb	Adverb
Centaurea cineraria	Yes	No	No	No
centaury	Yes	No	No	No

As nouns, centaury is a hypernym of Centaurea cineraria; that is, centaury is a word with a broader meaning than Centaurea cineraria:

Centaurea cineraria: a plant having leaves and stems covered with down that resembles dust
centaury: any plant of the genus Centaurea

Centaurea cineraria (noun)	centaury (noun)
a plant having leaves and stems covered with down that resembles dust	any plant of the genus Centaurea
	any of various plants of the genus Centaurium