broomweed vs matchbush

broomweed and matchbush both are nouns.

Word	Noun	Adjective	Verb	Adverb
broomweed	Yes	No	No	No
matchbush	Yes	No	No	No

As nouns, matchbush is a hypernym of broomweed; that is, matchbush is a word with a broader meaning than broomweed:

broomweed: annual of southwestern United States having rigid woody branches with sticky foliage and yellow flowers
matchbush: any of several plants of the genus Gutierrezia having tiny flower heads that resemble the heads of matches

Other hypernyms of broomweed include matchweed.

broomweed (noun)	matchbush (noun)
annual of southwestern United States having rigid woody branches with sticky foliage and yellow flowers	any of several plants of the genus Gutierrezia having tiny flower heads that resemble the heads of matches