wild celery vs herb

wild celery and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
wild celery	Yes	No	No	No
herb	Yes	No	No	No

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

wild celery: herb of Europe and temperate Asia
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 wild celery include herbaceous plant.

wild celery (noun)	herb (noun)
submerged aquatic plant with ribbonlike leaves; Old World and Australia	aromatic potherb used in cookery for its savory qualities
herb of Europe and temperate Asia	a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests