sweet flag vs calamus

sweet flag and calamus both are nouns.

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

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

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

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

sweet 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