order Laminariales vs class Phaeophyceae

order Laminariales and class Phaeophyceae both are nouns.

Word	Noun	Adjective	Verb	Adverb
order Laminariales	Yes	No	No	No
class Phaeophyceae	Yes	No	No	No

order Laminariales (noun)	class Phaeophyceae (noun)
in some classifications coextensive with family Laminariaceae: marine brown algae of cold or polar seas	brown algae; mostly marine and littoral eukaryotic algae