Brugmansia arborea vs shrub

Brugmansia arborea and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Brugmansia arborea	Yes	No	No	No
shrub	Yes	No	No	No

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

Brugmansia arborea: a South American plant that is cultivated for its large fragrant trumpet-shaped flowers
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Brugmansia arborea include bush.

Brugmansia arborea (noun)	shrub (noun)
a South American plant that is cultivated for its large fragrant trumpet-shaped flowers	a low woody perennial plant usually having several major stems