horsefly weed vs indigo broom

horsefly weed and indigo broom both are nouns.

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

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

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

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

horsefly 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