California redbud vs shrub

California redbud and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
California redbud	Yes	No	No	No
shrub	Yes	No	No	No

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

California redbud: shrub of western United States having pink or crimson flowers; often forms thickets
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of California redbud include bush.

California redbud (noun)	shrub (noun)
shrub of western United States having pink or crimson flowers; often forms thickets	a low woody perennial plant usually having several major stems