bluestem vs blue stem

bluestem and blue stem both are nouns.

Word	Noun	Adjective	Verb	Adverb
bluestem	Yes	No	No	No
blue stem	Yes	No	No	No

As nouns, bluestem and blue stem are synonyms defined as:

bluestem and blue stem: tall grass with smooth bluish leaf sheaths grown for hay in the United States

Other synonyms of bluestem include Andropogon furcatus, Andropogon gerardii.

bluestem (noun)	blue stem (noun)
tall grass with smooth bluish leaf sheaths grown for hay in the United States	tall grass with smooth bluish leaf sheaths grown for hay in the United States