yellow salsify vs wild flower

yellow salsify and wild flower both are nouns.

Word	Noun	Adjective	Verb	Adverb
yellow salsify	Yes	No	No	No
wild flower	Yes	No	No	No

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

yellow salsify: European perennial naturalized throughout United States having hollow stems with a few long narrow tapered leaves and each bearing a solitary pale yellow flower
wild flower: wild or uncultivated flowering plant

Other hypernyms of yellow salsify include wildflower.

yellow salsify (noun)	wild flower (noun)
European perennial naturalized throughout United States having hollow stems with a few long narrow tapered leaves and each bearing a solitary pale yellow flower	wild or uncultivated flowering plant