cryptocoryne vs water plant

cryptocoryne and water plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
cryptocoryne	Yes	No	No	No
water plant	Yes	No	No	No

As nouns, water plant is a hypernym of cryptocoryne; that is, water plant is a word with a broader meaning than cryptocoryne:

cryptocoryne: any plant of the genus Cryptocoryne; evergreen perennials growing in fresh or brackish water; tropical Asia
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 cryptocoryne include aquatic plant, hydrophyte, hydrophytic plant.

cryptocoryne (noun)	water plant (noun)
any plant of the genus Cryptocoryne; evergreen perennials growing in fresh or brackish water; tropical Asia	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