Lupinus arboreus vs tree lupine

Lupinus arboreus and tree lupine both are nouns.

Word	Noun	Adjective	Verb	Adverb
Lupinus arboreus	Yes	No	No	No
tree lupine	Yes	No	No	No

As nouns, Lupinus arboreus and tree lupine are synonyms defined as:

Lupinus arboreus and tree lupine: evergreen shrub of the Pacific coast of the United States having showy yellow or blue flowers; naturalized in Australia

Lupinus arboreus (noun)	tree lupine (noun)
evergreen shrub of the Pacific coast of the United States having showy yellow or blue flowers; naturalized in Australia	evergreen shrub of the Pacific coast of the United States having showy yellow or blue flowers; naturalized in Australia