sweet flag vs sweet calamus

sweet flag and sweet calamus both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweet flag	Yes	No	No	No
sweet calamus	Yes	No	No	No

As nouns, sweet flag and sweet calamus are synonyms defined as:

sweet flag and sweet calamus: perennial marsh plant having swordlike leaves and aromatic roots

Other synonyms of sweet flag include Acorus calamus, calamus, flagroot, myrtle flag.

sweet flag (noun)	sweet calamus (noun)
perennial marsh plant having swordlike leaves and aromatic roots	perennial marsh plant having swordlike leaves and aromatic roots