western mugwort vs cudweed

western mugwort and cudweed both are nouns.

Word	Noun	Adjective	Verb	Adverb
western mugwort	Yes	No	No	No
cudweed	Yes	No	No	No

As nouns, western mugwort and cudweed are synonyms defined as:

western mugwort and cudweed: perennial cottony-white herb of southwestern United States

Other synonyms of western mugwort include Artemisia gnaphalodes, Artemisia ludoviciana, prairie sage, white sage.

western mugwort (noun)	cudweed (noun)
perennial cottony-white herb of southwestern United States	any of numerous plants of the genus Gnaphalium having flowers that can be dried without loss of form or color
	any plant of the genus Filago having capitate clusters of small woolly flower heads
	perennial cottony-white herb of southwestern United States