rattle weed vs indigo broom

rattle weed and indigo broom both are nouns.

Word	Noun	Adjective	Verb	Adverb
rattle weed	Yes	No	No	No
indigo broom	Yes	No	No	No

As nouns, rattle weed and indigo broom are synonyms defined as:

rattle weed and indigo broom: much-branched erect herb with bright yellow flowers; distributed from Massachusetts to Florida

Other synonyms of rattle weed include Baptisia tinctoria, horsefly weed.

rattle weed (noun)	indigo broom (noun)
much-branched erect herb with bright yellow flowers; distributed from Massachusetts to Florida	much-branched erect herb with bright yellow flowers; distributed from Massachusetts to Florida