trumpet weed vs marsh milkweed

trumpet weed and marsh milkweed both are nouns.

Word	Noun	Adjective	Verb	Adverb
trumpet weed	Yes	No	No	No
marsh milkweed	Yes	No	No	No

As nouns, trumpet weed and marsh milkweed are synonyms defined as:

trumpet weed and marsh milkweed: North American herb having whorled leaves and terminal clusters of flowers spotted with purple

Other synonyms of trumpet weed include Eupatorium purpureum, Joe-Pye weed, purple boneset.

trumpet weed (noun)	marsh milkweed (noun)
North American herb having whorled leaves and terminal clusters of flowers spotted with purple	North American herb having whorled leaves and terminal clusters of flowers spotted with purple