indian mustard vs Brassica juncea

indian mustard and Brassica juncea both are nouns.

Word	Noun	Adjective	Verb	Adverb
indian mustard	Yes	No	No	No
Brassica juncea	Yes	No	No	No

As nouns, indian mustard and Brassica juncea are synonyms defined as:

Other synonyms of indian mustard include chinese mustard, gai choi, leaf mustard.

indian mustard (noun)	Brassica juncea (noun)
Asiatic mustard used as a potherb	Asiatic mustard used as a potherb