Photinia arbutifolia vs shrub

Photinia arbutifolia and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Photinia arbutifolia	Yes	No	No	No
shrub	Yes	No	No	No

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

Photinia arbutifolia: ornamental evergreen treelike shrub of the Pacific coast of the United States having large white flowers and red berrylike fruits; often placed in genus Photinia
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Photinia arbutifolia include bush.

Photinia arbutifolia (noun)	shrub (noun)
ornamental evergreen treelike shrub of the Pacific coast of the United States having large white flowers and red berrylike fruits; often placed in genus Photinia	a low woody perennial plant usually having several major stems