gayfeather vs wild flower

gayfeather and wild flower both are nouns.

Word	Noun	Adjective	Verb	Adverb
gayfeather	Yes	No	No	No
wild flower	Yes	No	No	No

As nouns, wild flower is a hypernym of gayfeather; that is, wild flower is a word with a broader meaning than gayfeather:

gayfeather: any of various North American plants of the genus Liatris having racemes or panicles of small discoid flower heads
wild flower: wild or uncultivated flowering plant

Other hypernyms of gayfeather include wildflower.

gayfeather (noun)	wild flower (noun)
any of various North American plants of the genus Liatris having racemes or panicles of small discoid flower heads	wild or uncultivated flowering plant