Indian paintbrush vs wildflower

Indian paintbrush and wildflower both are nouns.

Word	Noun	Adjective	Verb	Adverb
Indian paintbrush	Yes	No	No	No
wildflower	Yes	No	No	No

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

Indian paintbrush: any of various plants of the genus Castilleja having dense spikes of hooded flowers with brightly colored bracts
wildflower: wild or uncultivated flowering plant

Other hypernyms of Indian paintbrush include wild flower.

Indian paintbrush (noun)	wildflower (noun)
any of various plants of the genus Castilleja having dense spikes of hooded flowers with brightly colored bracts	wild or uncultivated flowering plant
erect perennial of eastern and southern United States having showy orange flowers