Ribes rubrum vs currant bush

Ribes rubrum and currant bush both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ribes rubrum	Yes	No	No	No
currant bush	Yes	No	No	No

As nouns, currant bush is a hypernym of Ribes rubrum; that is, currant bush is a word with a broader meaning than Ribes rubrum:

Ribes rubrum: cultivated European current bearing small edible red berries
currant bush: any of various deciduous shrubs of the genus Ribes bearing currants

Other hypernyms of Ribes rubrum include currant.

Ribes rubrum (noun)	currant bush (noun)
cultivated European current bearing small edible red berries	any of various deciduous shrubs of the genus Ribes bearing currants