pistia vs hydrophyte

pistia and hydrophyte both are nouns.

Word	Noun	Adjective	Verb	Adverb
pistia	Yes	No	No	No
hydrophyte	Yes	No	No	No

As nouns, hydrophyte is a hypernym of pistia; that is, hydrophyte is a word with a broader meaning than pistia:

pistia: pantropical floating plant forming a rosette of wedge-shaped leaves; a widespread weed in rivers and lakes
hydrophyte: 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 pistia include aquatic plant, hydrophytic plant, water plant.

pistia (noun)	hydrophyte (noun)
pantropical floating plant forming a rosette of wedge-shaped leaves; a widespread weed in rivers and lakes	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