field speedwell vs veronica

field speedwell and veronica both are nouns.

Word	Noun	Adjective	Verb	Adverb
field speedwell	Yes	No	No	No
veronica	Yes	No	No	No

As nouns, veronica is a hypernym of field speedwell; that is, veronica is a word with a broader meaning than field speedwell:

field speedwell: European plant with minute axillary blue flowers on long stalks; widely naturalized in America
veronica: any plant of the genus Veronica

Other hypernyms of field speedwell include speedwell.

field speedwell (noun)	veronica (noun)
European plant with minute axillary blue flowers on long stalks; widely naturalized in America	any plant of the genus Veronica