round kumquat vs Fortunella japonica

round kumquat and Fortunella japonica both are nouns.

Word	Noun	Adjective	Verb	Adverb
round kumquat	Yes	No	No	No
Fortunella japonica	Yes	No	No	No

As nouns, round kumquat and Fortunella japonica are synonyms defined as:

round kumquat and Fortunella japonica: shrub bearing round-fruited kumquats

Other synonyms of round kumquat include marumi, marumi kumquat.

round kumquat (noun)	Fortunella japonica (noun)
shrub bearing round-fruited kumquats	shrub bearing round-fruited kumquats