Penstemon heterodoxus is a species of penstemon known by the common name Sierra beardtongue. It is native to California and western Nevada where it grows in several of the mountain ranges from the Klamath Mountains to the Sierra Nevada and the slopes and plateaus to the east. It grows in subalpine and alpine climates in mountain forests, meadows and talus. It is a perennial herb growing stems upright 65 centimeters in maximum height or in a low, spreading mat. The leaves are lance-shaped to oblong, the upper pairs sometimes clasping the stem. The hairy flower cluster is made up of 1 to 6 separate clusters of dark purple-blue tubular flowers each just over a centimeter long. The outer surface of the flower generally has hairy hairs, and on the inside there are hairs on the floor of the flower mouth and on the staminode.