baby blue-eyes vs herb

baby blue-eyes and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
baby blue-eyes	Yes	No	No	No
herb	Yes	No	No	No

As nouns, herb is a hypernym of baby blue-eyes; that is, herb is a word with a broader meaning than baby blue-eyes:

baby blue-eyes: delicate California annual having blue flowers marked with dark spots
herb: a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests

Other hypernyms of baby blue-eyes include herbaceous plant.

baby blue-eyes (noun)	herb (noun)
delicate California annual having blue flowers marked with dark spots	aromatic potherb used in cookery for its savory qualities
	a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests