prairie star vs wild flower

prairie star and wild flower both are nouns.

Word	Noun	Adjective	Verb	Adverb
prairie star	Yes	No	No	No
wild flower	Yes	No	No	No

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

prairie star: plant with mostly basal leaves and slender open racemes of white or pale pink flowers; prairies and open forest of northwestern United States to British Columbia and Alberta
wild flower: wild or uncultivated flowering plant

Other hypernyms of prairie star include wildflower.

prairie star (noun)	wild flower (noun)
plant with mostly basal leaves and slender open racemes of white or pale pink flowers; prairies and open forest of northwestern United States to British Columbia and Alberta	wild or uncultivated flowering plant