genus Zostera vs grass wrack

genus Zostera and grass wrack both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Zostera	Yes	No	No	No
grass wrack	Yes	No	No	No

genus Zostera (noun)	grass wrack (noun)
(or in some classifications family Zosteraceae) small genus of widely distributed marine plants	submerged marine plant with very long narrow leaves found in abundance along North Atlantic coasts