black saltwort vs sea milkwort

black saltwort and sea milkwort both are nouns.

Word	Noun	Adjective	Verb	Adverb
black saltwort	Yes	No	No	No
sea milkwort	Yes	No	No	No

As nouns, black saltwort and sea milkwort are synonyms defined as:

black saltwort and sea milkwort: a small fleshy herb common along North American seashores and in brackish marshes having pink or white flowers

Other synonyms of black saltwort include Glaux maritima, sea trifoly.

black saltwort (noun)	sea milkwort (noun)
a small fleshy herb common along North American seashores and in brackish marshes having pink or white flowers	a small fleshy herb common along North American seashores and in brackish marshes having pink or white flowers