Martynia arenaria vs herb

Martynia arenaria and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
Martynia arenaria	Yes	No	No	No
herb	Yes	No	No	No

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

Martynia arenaria: alternatively placed in genus Martynia
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 Martynia arenaria include herbaceous plant.

Martynia arenaria (noun)	herb (noun)
alternatively placed in genus Martynia	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