Mono penstemon, Penstemon monoensis, California, White Mountains, Coldwater Canyon, Chalfant Valley - Owens Valley drainage, elevation 1631 m (5350 ft).

This rare species is found only along the lower west slopes of the White and Inyo Mountains bordering Owens Valley in Inyo and southern Mono counties, California. It prefers dry rocky calcareous soils and outcrops at desert elevations of 1200-1800 meters (3900-5900 feet). Its nearest relative is thought to be Penstemon calcareus from the Death Valley region farther south and east.

Ironically the only known Mono County occurrences of this species are in the canyon where these images were taken, about a mile north of the county line. If the type specimens hadn't just happened to be collected here in 1906, there's a good chance the species would have been named P. inyoensis instead!