wild celery vs aquatic plant

wild celery and aquatic plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
wild celery	Yes	No	No	No
aquatic plant	Yes	No	No	No

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

wild celery: submerged aquatic plant with ribbonlike leaves; Old World and Australia
aquatic plant: a plant that grows partly or wholly in water whether rooted in the mud, as a lotus, or floating without anchorage, as the water hyacinth

Other hypernyms of wild celery include hydrophyte, hydrophytic plant, water plant.

wild celery (noun)	aquatic plant (noun)
submerged aquatic plant with ribbonlike leaves; Old World and Australia	a plant that grows partly or wholly in water whether rooted in the mud, as a lotus, or floating without anchorage, as the water hyacinth
herb of Europe and temperate Asia