dayflower vs herb

dayflower and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
dayflower	Yes	No	No	No
herb	Yes	No	No	No

As nouns, herb is a hypernym of dayflower; that is, herb is a word with a broader meaning than dayflower:

dayflower: any plant of the family Commelinaceae
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 dayflower include herbaceous plant.

dayflower (noun)	herb (noun)
any plant of the family Commelinaceae	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