eelgrass vs Vallisneria spiralis

eelgrass and Vallisneria spiralis both are nouns.

Word	Noun	Adjective	Verb	Adverb
eelgrass	Yes	No	No	No
Vallisneria spiralis	Yes	No	No	No

As nouns, eelgrass and Vallisneria spiralis are synonyms defined as:

eelgrass and Vallisneria spiralis: submerged aquatic plant with ribbonlike leaves; Old World and Australia

Other synonyms of eelgrass include tape grass, wild celery.

eelgrass (noun)	Vallisneria spiralis (noun)
submerged marine plant with very long narrow leaves found in abundance along North Atlantic coasts	submerged aquatic plant with ribbonlike leaves; Old World and Australia
submerged aquatic plant with ribbonlike leaves; Old World and Australia