Benjamin bush vs shrub

Benjamin bush and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Benjamin bush	Yes	No	No	No
shrub	Yes	No	No	No

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

Benjamin bush: deciduous shrub of the eastern United States having highly aromatic leaves and bark and yellow flowers followed by scarlet or yellow berries
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Benjamin bush include bush.

Benjamin bush (noun)	shrub (noun)
deciduous shrub of the eastern United States having highly aromatic leaves and bark and yellow flowers followed by scarlet or yellow berries	a low woody perennial plant usually having several major stems