desert sunflower vs wildflower

desert sunflower and wildflower both are nouns.

Word	Noun	Adjective	Verb	Adverb
desert sunflower	Yes	No	No	No
wildflower	Yes	No	No	No

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

desert sunflower: slender hairy plant with few leaves and golden-yellow flower heads; sandy desert areas of southeastern California to southwestern Utah and western Arizona and northwestern Mexico
wildflower: wild or uncultivated flowering plant

Other hypernyms of desert sunflower include wild flower.

desert sunflower (noun)	wildflower (noun)
slender hairy plant with few leaves and golden-yellow flower heads; sandy desert areas of southeastern California to southwestern Utah and western Arizona and northwestern Mexico	wild or uncultivated flowering plant