pakchoi vs Brassica rapa chinensis

pakchoi and Brassica rapa chinensis both are nouns.

Word	Noun	Adjective	Verb	Adverb
pakchoi	Yes	No	No	No
Brassica rapa chinensis	Yes	No	No	No

As nouns, pakchoi and Brassica rapa chinensis are synonyms defined as:

pakchoi and Brassica rapa chinensis: Asiatic plant grown for its cluster of edible white stalks with dark green leaves

Other synonyms of pakchoi include bok choi, bok choy, Chinese white cabbage, pak choi.

pakchoi (noun)	Brassica rapa chinensis (noun)
Asiatic plant grown for its cluster of edible white stalks with dark green leaves	Asiatic plant grown for its cluster of edible white stalks with dark green leaves