frog's-bit vs water plant

frog's-bit and water plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
frog's-bit	Yes	No	No	No
water plant	Yes	No	No	No

As nouns, water plant is a hypernym of frog's-bit; that is, water plant is a word with a broader meaning than frog's-bit:

frog's-bit: European floating plant with roundish heart-shaped leaves and white flowers
water 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 frog's-bit include aquatic plant, hydrophyte, hydrophytic plant.

frog's-bit (noun)	water plant (noun)
European floating plant with roundish heart-shaped leaves and white flowers	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