Egyptian henbane vs herb

Egyptian henbane and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
Egyptian henbane	Yes	No	No	No
herb	Yes	No	No	No

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

Egyptian henbane: poisonous herb whose leaves are a source of hyoscyamine
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 Egyptian henbane include herbaceous plant.

Egyptian henbane (noun)	herb (noun)
poisonous herb whose leaves are a source of hyoscyamine	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