cascade penstemon vs genus Penstemon

cascade penstemon and genus Penstemon both are nouns.

Word	Noun	Adjective	Verb	Adverb
cascade penstemon	Yes	No	No	No
genus Penstemon	Yes	No	No	No

cascade penstemon (noun)	genus Penstemon (noun)
whorls of deep blue to dark purple flowers at tips of erect leafy stems; moist places from British Columbia to Oregon	large genus of subshrubs or herbs having showy blue or purple or red or yellow or white flowers; mostly western North America