Lupinus arboreus vs shrub

Lupinus arboreus and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Lupinus arboreus	Yes	No	No	No
shrub	Yes	No	No	No

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

Lupinus arboreus: evergreen shrub of the Pacific coast of the United States having showy yellow or blue flowers; naturalized in Australia
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Lupinus arboreus include bush.

Lupinus arboreus (noun)	shrub (noun)
evergreen shrub of the Pacific coast of the United States having showy yellow or blue flowers; naturalized in Australia	a low woody perennial plant usually having several major stems