Penstemon roezlii is a small purple /blue Penstemon of the Sierra Nevada and Cascade ranges. This little species will take dry conditions in stride and is one of the best filler plants in my dry garden. It seeds around is open in habit and tough as nails. You will find it on dry foothill slopes and high mountain crests. In my experiance it prefers some clay in the grainy soil mixes it grows on.
http://www.calflora.org/cgi-bin/species_query.cgi?where-taxon=Penstemon+...
http://plants.usda.gov/java/nameSearch?keywordquery=Penstemon%20roezlii&...
http://science.halleyhosting.com/nature/cascade/5petal/figwort/penstemon...
