trailing arbutus vs shrub

trailing arbutus and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
trailing arbutus	Yes	No	No	No
shrub	Yes	No	No	No

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

trailing arbutus: low-growing evergreen shrub of eastern North America with leathery leaves and clusters of fragrant pink or white flowers
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of trailing arbutus include bush.

trailing arbutus (noun)	shrub (noun)
low-growing evergreen shrub of eastern North America with leathery leaves and clusters of fragrant pink or white flowers	a low woody perennial plant usually having several major stems