Pieris floribunda vs shrub

Pieris floribunda and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pieris floribunda	Yes	No	No	No
shrub	Yes	No	No	No

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

Pieris floribunda: ornamental evergreen shrub of southeastern United States having small white bell-shaped flowers
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Pieris floribunda include bush.

Pieris floribunda (noun)	shrub (noun)
ornamental evergreen shrub of southeastern United States having small white bell-shaped flowers	a low woody perennial plant usually having several major stems