Stems ascending to erect, (15–)30–70 cm, glabrous, not glaucous. Leaves basal and cauline, leathery or not, glabrous, not glaucous; basal and proximal cauline 80–140(–180) × (10–)15–35(–40) mm, blade ovate to elliptic, base tapered, margins entire, apex obtuse to acute; cauline 5–7 pairs, sessile, (28–)40–80(–110) × 6–30(–42) mm, blade ovate to lanceolate, base tapered to cordate-clasping, apex acute. Thyrses continuous, sometimes interrupted proximally, cylindric, (3–)8–32 cm, axis glabrous, verticillasters 4–10(–16), cymes 2–4(–8)-flowered, 2 per node; proximal bracts ovate to lanceolate, 12–80 × 2–35 mm; peduncles and pedicels glabrous. Flowers: calyx lobes lanceolate, 5–8.5(–10) × 1–2 mm, glabrous; corolla blue to violet, without nectar guides, ventricose, 18–22 mm, glabrous externally, glabrous internally, tube 6–9 mm, throat gradually inflated, not constricted at orifice, 7–10 mm diam., slightly 2-ridged abaxially; stamens: longer pair reaching orifice or slightly exserted, pollen sacs opposite, navicular, 1.2–1.9 mm, dehiscing incompletely, connective not splitting, sides glabrous, sutures denticulate, teeth to 0.1 mm; staminode: 13–15 mm, included, 0.5–0.9 mm diam., tip straight, distal 2–3 mm sparsely pilose, sometimes glabrous, hairs yellow, to 0.5 mm; style 13–17 mm. Capsules 8–15 × 5–8 mm. 2n = 16.
Phenology: Flowering May–Aug.
Habitat: Gravelly sagebrush shrublands, open coniferous forests.
Elevation: 1200–2600 m.
Idaho, Mont., Oreg.
Penstemon payettensis is known from the Northern Rocky Mountains and eastern Columbia Plateau.