Univ. Calif. Publ. Bot. 16: 398, fig. 13. 1932.
Subshrubs. Stems ascending to erect, 20–80 cm, glabrous, sometimes ± puberulent, hairs pointed, glaucous. Leaves basal and cauline, basal sometimes few, opposite, glabrous, sometimes proximals puberulent, hairs pointed, glaucous; basal and proximal cauline 15–80 × 2–10 mm, blade spatulate to oblanceolate, base tapered, margins entire, apex rounded to obtuse or acute; cauline 4–6 pairs, sessile, 20–80 × 3–9 mm, blade ovate to lanceolate, base tapered, margins entire, apex acute. Thyrses interrupted, cylindric, 5–25 cm, axis glandular-pubescent, verticillasters 4–6, cymes 1–3-flowered, 2 per node; proximal bracts ovate to lanceolate, 4–50 × 1–8 mm; peduncles and pedicels ascending, glandular-pubescent. Flowers: calyx lobes ovate to lanceolate, 3.8–6 × 1.5–2.2 mm, glandular-pubescent; corolla violet to blue or purple, without nectar guides, ventricose to ventricose-ampliate, 25–38 mm, glandular-pubescent externally, glabrous internally, tube 7–9 mm, throat gradually inflated, 8–10 mm diam., 2-ridged abaxially; stamens included, filaments glabrous, pollen sacs parallel, 2.4–3.2 mm, distal 1/5–1/3 indehiscent, sides pilose to lanate, hairs white, to 0.6 mm near filament attachment, sutures denticulate, teeth to 0.2 mm; staminode 11–15 mm, included, 0.4–0.6 mm diam., glabrous; style 15–20 mm. Capsules 7–9 × 4–5 mm. 2n = 64.
Phenology: Flowering May–Aug(–Oct).
Habitat: Volcanic soils, scrub, open pine and fir forests.
Elevation: 1000–2200 m.
Penstemon neotericus is known from the Cascade Range and northern Sierra Nevada of northern California (Butte, Lassen, Placer, Plumas, Shasta, Sierra, Siskiyou, Tehama, and Yuba counties). D. D. Keck (1932) used morphologic and geographic data to hypothesize that P. neotericus, an octoploid, arose through hybridization between P. azureus and P. laetus. J. Clausen (1933) provided cytological evidence supporting that hypothesis. A diploid chromosome number of 2n = 32 listed by N. H. Holmgren (1993) is probably a transcription error.