bladderwrack vs black rockweed

bladderwrack and black rockweed both are nouns.

Word	Noun	Adjective	Verb	Adverb
bladderwrack	Yes	No	No	No
black rockweed	Yes	No	No	No

As nouns, bladderwrack and black rockweed are synonyms defined as:

bladderwrack and black rockweed: a common rockweed used in preparing kelp and as manure

Other synonyms of bladderwrack include bladder fucus, Fucus vesiculosus, tang.

bladderwrack (noun)	black rockweed (noun)
a common rockweed used in preparing kelp and as manure	a common rockweed used in preparing kelp and as manure
similar to and found with black rockweed