hogweed vs herb

hogweed and herb both are nouns.

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

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

hogweed: tall coarse plant having thick stems and cluster of white to purple flowers
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 hogweed include herbaceous plant.

hogweed (noun)	herb (noun)
tall coarse plant having thick stems and cluster of white to purple flowers	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