shrubby penstemon vs Penstemon fruticosus

shrubby penstemon and Penstemon fruticosus both are nouns.

Word	Noun	Adjective	Verb	Adverb
shrubby penstemon	Yes	No	No	No
Penstemon fruticosus	Yes	No	No	No

As nouns, shrubby penstemon and Penstemon fruticosus are synonyms defined as:

shrubby penstemon and Penstemon fruticosus: low bushy plant with large showy pale lavender or blue-violet flowers in narrow clusters at ends of stems

Other synonyms of shrubby penstemon include lowbush penstemon.

shrubby penstemon (noun)	Penstemon fruticosus (noun)
low bushy plant with large showy pale lavender or blue-violet flowers in narrow clusters at ends of stems	low bushy plant with large showy pale lavender or blue-violet flowers in narrow clusters at ends of stems