genus Penstemon vs Penstemon davidsonii

genus Penstemon and Penstemon davidsonii both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Penstemon	Yes	No	No	No
Penstemon davidsonii	Yes	No	No	No

genus Penstemon (noun)	Penstemon davidsonii (noun)
large genus of subshrubs or herbs having showy blue or purple or red or yellow or white flowers; mostly western North America	mat-forming plant with blue and lavender flowers clustered on short erect stems; British Columbia to northern California