devil's walking stick vs shrub

devil's walking stick and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
devil's walking stick	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of devil's walking stick; that is, shrub is a word with a broader meaning than devil's walking stick:

devil's walking stick: small deciduous clump-forming tree or shrub of eastern United States
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of devil's walking stick include bush.

devil's walking stick (noun)	shrub (noun)
small deciduous clump-forming tree or shrub of eastern United States	a low woody perennial plant usually having several major stems