butterweed vs wildflower

butterweed and wildflower both are nouns.

Word	Noun	Adjective	Verb	Adverb
butterweed	Yes	No	No	No
wildflower	Yes	No	No	No

As nouns, wildflower is a hypernym of butterweed; that is, wildflower is a word with a broader meaning than butterweed:

Other hypernyms of butterweed include wild flower.

butterweed (noun)	wildflower (noun)
any of several yellow-flowered plants of the genus Packera; often placed in genus Senecio	wild or uncultivated flowering plant
American ragwort with yellow flowers