myrtle flag vs calamus

myrtle flag and calamus both are nouns.

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

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

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

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

myrtle flag (noun)	calamus (noun)
perennial marsh plant having swordlike leaves and aromatic roots	the hollow spine of a feather
	any tropical Asian palm of the genus Calamus; light tough stems are a source of rattan canes
	perennial marsh plant having swordlike leaves and aromatic roots
	the aromatic root of the sweet flag used medicinally