Pyxidanthera barbulata vs shrub

Pyxidanthera barbulata and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pyxidanthera barbulata	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of Pyxidanthera barbulata; that is, shrub is a word with a broader meaning than Pyxidanthera barbulata:

Pyxidanthera barbulata: creeping evergreen shrub having narrow overlapping leaves and early white star-shaped flowers; of the pine barrens of New Jersey and the Carolinas
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Pyxidanthera barbulata include bush.

Pyxidanthera barbulata (noun)	shrub (noun)
creeping evergreen shrub having narrow overlapping leaves and early white star-shaped flowers; of the pine barrens of New Jersey and the Carolinas	a low woody perennial plant usually having several major stems