Penstemon virens

Penstemon virens, commonly known as blue mist penstemon, Front Range penstemon, or Green beardtongue, is a common Penstemon in the Front Range foothills in Colorado and Wyoming. The dainty flowers are an ornament to many rocky or sandy area within its range. It is confusingly similar to Penstemon humilis and Penstemon albertinus though the ranges of these plants do not overlap in the wild. The origin of calling it the "blue mist penstemon" is not precisely known, but is thought to relate to the large number of blue flowers the plant can produce reminding observers of a blue mist....read more on Wikipedia.