gesneria vs herb

gesneria and herb both are nouns.

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

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

gesneria: any plant of the genus Gesneria
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 gesneria include herbaceous plant.

gesneria (noun)	herb (noun)
any plant of the genus Gesneria	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