marsh milkweed vs Joe-Pye weed

marsh milkweed and Joe-Pye weed both are nouns.

Word	Noun	Adjective	Verb	Adverb
marsh milkweed	Yes	No	No	No
Joe-Pye weed	Yes	No	No	No

As nouns, marsh milkweed and Joe-Pye weed are synonyms defined as:

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

Other synonyms of marsh milkweed include Eupatorium purpureum, purple boneset, trumpet weed.

marsh milkweed (noun)	Joe-Pye weed (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 small pinkish or purple flower heads
	North American herb having whorled leaves and terminal clusters of flowers spotted with purple