flannelbush vs shrub

flannelbush and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
flannelbush	Yes	No	No	No
shrub	Yes	No	No	No

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

flannelbush: any of several handsome evergreen shrubs of California and northern Mexico having downy lobed leaves and showy yellow flowers
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of flannelbush include bush.

flannelbush (noun)	shrub (noun)
any of several handsome evergreen shrubs of California and northern Mexico having downy lobed leaves and showy yellow flowers	a low woody perennial plant usually having several major stems