sour orange vs Citrus aurantium

sour orange and Citrus aurantium both are nouns.

Word	Noun	Adjective	Verb	Adverb
sour orange	Yes	No	No	No
Citrus aurantium	Yes	No	No	No

As nouns, sour orange and Citrus aurantium are synonyms defined as:

sour orange and Citrus aurantium: any of various common orange trees yielding sour or bitter fruit; used as grafting stock

Other synonyms of sour orange include bigarade, bitter orange, bitter orange tree, marmalade orange, Seville orange.

sour orange (noun)	Citrus aurantium (noun)
highly acidic orange used especially in marmalade	any of various common orange trees yielding sour or bitter fruit; used as grafting stock
any of various common orange trees yielding sour or bitter fruit; used as grafting stock