Alisma plantago-aquatica vs water plantain

Alisma plantago-aquatica and water plantain both are nouns.

Word	Noun	Adjective	Verb	Adverb
Alisma plantago-aquatica	Yes	No	No	No
water plantain	Yes	No	No	No

As nouns, Alisma plantago-aquatica and water plantain are synonyms defined as:

Alisma plantago-aquatica and water plantain: marsh plant having clusters of small white or pinkish flowers and broad pointed or rounded leaves

Alisma plantago-aquatica (noun)	water plantain (noun)
marsh plant having clusters of small white or pinkish flowers and broad pointed or rounded leaves	marsh plant having clusters of small white or pinkish flowers and broad pointed or rounded leaves