lowbush penstemon vs shrubby penstemon

lowbush penstemon and shrubby penstemon both are nouns.

Word	Noun	Adjective	Verb	Adverb
lowbush penstemon	Yes	No	No	No
shrubby penstemon	Yes	No	No	No

As nouns, lowbush penstemon and shrubby penstemon are synonyms defined as:

lowbush penstemon and shrubby penstemon: 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 Penstemon fruticosus.

lowbush penstemon (noun)	shrubby penstemon (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