narrow-leaf penstemon vs Penstemon linarioides

narrow-leaf penstemon and Penstemon linarioides both are nouns.

Word	Noun	Adjective	Verb	Adverb
narrow-leaf penstemon	Yes	No	No	No
Penstemon linarioides	Yes	No	No	No

As nouns, narrow-leaf penstemon and Penstemon linarioides are synonyms defined as:

narrow-leaf penstemon and Penstemon linarioides: plant having small narrow leaves and blue-violet flowers in long open clusters; Utah and Colorado to New Mexico and Arizona

narrow-leaf penstemon (noun)	Penstemon linarioides (noun)
plant having small narrow leaves and blue-violet flowers in long open clusters; Utah and Colorado to New Mexico and Arizona	plant having small narrow leaves and blue-violet flowers in long open clusters; Utah and Colorado to New Mexico and Arizona