red shrubby penstemon vs Penstemon

red shrubby penstemon and Penstemon both are nouns.

Word	Noun	Adjective	Verb	Adverb
red shrubby penstemon	Yes	No	No	No
Penstemon	Yes	No	No	No

red shrubby penstemon (noun)	Penstemon (noun)
low branching dark green shrub with bunches of brick-red flowers at ends of branches; coastal ranges and foothills of northern California	large genus of subshrubs or herbs having showy blue or purple or red or yellow or white flowers; mostly western North America