pitcher sage vs shrub

pitcher sage and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
pitcher sage	Yes	No	No	No
shrub	Yes	No	No	No

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

pitcher sage: California plant with woolly stems and leaves and large white flowers
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of pitcher sage include bush.

pitcher sage (noun)	shrub (noun)
California plant with woolly stems and leaves and large white flowers	a low woody perennial plant usually having several major stems
California erect and sparsely branched perennial