myrtle flag vs sweet flag

myrtle flag and sweet flag both are nouns.

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

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

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

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

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