Fortunella margarita vs cumquat

Fortunella margarita and cumquat both are nouns.

Word	Noun	Adjective	Verb	Adverb
Fortunella margarita	Yes	No	No	No
cumquat	Yes	No	No	No

As nouns, cumquat is a hypernym of Fortunella margarita; that is, cumquat is a word with a broader meaning than Fortunella margarita:

Fortunella margarita: shrub bearing oval-fruited kumquats
cumquat: any of several trees or shrubs of the genus Fortunella bearing small orange-colored edible fruits with thick sweet-flavored skin and sour pulp

Other hypernyms of Fortunella margarita include kumquat, kumquat tree.

Fortunella margarita (noun)	cumquat (noun)
shrub bearing oval-fruited kumquats	any of several trees or shrubs of the genus Fortunella bearing small orange-colored edible fruits with thick sweet-flavored skin and sour pulp