tape grass vs aquatic plant

tape grass and aquatic plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
tape grass	Yes	No	No	No
aquatic plant	Yes	No	No	No

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

tape grass: 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 tape grass include hydrophyte, hydrophytic plant, water plant.

tape grass (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