Rosa multiflora vs rosebush

Rosa multiflora and rosebush both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rosa multiflora	Yes	No	No	No
rosebush	Yes	No	No	No

As nouns, rosebush is a hypernym of Rosa multiflora; that is, rosebush is a word with a broader meaning than Rosa multiflora:

Rosa multiflora: vigorously growing rose having clusters of numerous small flowers; used for hedges and as grafting stock
rosebush: any of many shrubs of the genus Rosa that bear roses

Other hypernyms of Rosa multiflora include rose.

Rosa multiflora (noun)	rosebush (noun)
vigorously growing rose having clusters of numerous small flowers; used for hedges and as grafting stock	any of many shrubs of the genus Rosa that bear roses