Nemophila menziesii vs herb

Nemophila menziesii and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
Nemophila menziesii	Yes	No	No	No
herb	Yes	No	No	No

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

Nemophila menziesii: 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 Nemophila menziesii include herbaceous plant.

Nemophila menziesii (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