pokeweed vs herb

pokeweed and herb both are nouns.

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

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

pokeweed: perennial of the genus Phytolacca
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 pokeweed include herbaceous plant.

pokeweed (noun)	herb (noun)
perennial of the genus Phytolacca	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