It is easy to confuse this Penstemon species with the Penstemon hybrid 'Rubicundus,'. However the hybrid by this name is a large red flower with a white throat, whereas the species P. rubicundus has large pink, some what baggy flowers on 2-3 foot tall stems.
This tall showy perennial is a rare native of the Wassuk Range of western Nevada.
It is believed that this is a naturally occurring hybrid between Penstemon palmeri and Penstemon floridus.
The US fish and Wildlife Service botanists worry that P. palmeri seed, often found in western reclamation mixes, will be introduced into it's range and result in further hybridization. It is therefore a species of concern.
It is hard to find sources and photos that reference this species online, here is one source and two sets of photos. (one set is from my flickr sight)