shepherd's clock vs wildflower

shepherd's clock and wildflower both are nouns.

Word	Noun	Adjective	Verb	Adverb
shepherd's clock	Yes	No	No	No
wildflower	Yes	No	No	No

As nouns, wildflower is a hypernym of shepherd's clock; that is, wildflower is a word with a broader meaning than shepherd's clock:

shepherd's clock: weedy European annual with yellow flowers; naturalized in United States
wildflower: wild or uncultivated flowering plant

Other hypernyms of shepherd's clock include wild flower.

shepherd's clock (noun)	wildflower (noun)
weedy European annual with yellow flowers; naturalized in United States	wild or uncultivated flowering plant