lowbush penstemon vs Penstemon fruticosus

lowbush penstemon and Penstemon fruticosus both are nouns.

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

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

lowbush 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 lowbush penstemon include shrubby penstemon.

lowbush 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