white turnip vs Brassica rapa

white turnip and Brassica rapa both are nouns.

Word	Noun	Adjective	Verb	Adverb
white turnip	Yes	No	No	No
Brassica rapa	Yes	No	No	No

As nouns, white turnip and Brassica rapa are synonyms defined as:

white turnip and Brassica rapa: widely cultivated plant having a large fleshy edible white or yellow root

Other synonyms of white turnip include turnip.

white turnip (noun)	Brassica rapa (noun)
white root of a turnip plant	widely cultivated plant having a large fleshy edible white or yellow root
widely cultivated plant having a large fleshy edible white or yellow root