Bot. Gaz. 27: 455. 1899. (as Pentstemon purpusi)
Herbs. Stems decumbent to ascending, 8–20 cm, retrorsely hairy to pilose, hairs pointed, not glaucous. Leaves basal and cauline, opposite, canescent to pilose, hairs pointed, not glaucous; basal and proximal cauline 8–30 × 3–12 mm, blade round to spatulate or ovate, base tapered, margins entire or shallowly dentate or serrate, apex rounded to obtuse; cauline 2–6 pairs, short-petiolate or sessile, 15–30 × 4–10 mm, blade obovate to spatulate or oblanceolate, base tapered, margins entire, apex obtuse to acute. Thyrses interrupted or continuous, cylindric, 2–8(–15) cm, axis glandular-pubescent, verticillasters 2–6, cymes 1–3-flowered, 1 or 2 per node; proximal bracts lanceolate, (4–)9–20 × (0.5–)1.5–4 mm; peduncles and pedicels appressed, glandular-pubescent. Flowers: calyx lobes ovate to lanceolate, 5–9.5 × 1–2.2 mm, glandular-pubescent; corolla purple to violet, blue, or purple, with purple or violet nectar guides, funnelform, 25–31 mm, glandular-pubescent externally, glabrous internally, tube 8–10 mm, throat gradually inflated, 7–9 mm diam., 2-ridged abaxially; stamens: longer pair reaching orifice, filaments glabrous, pollen sacs parallel, 2.4–2.6 mm, distal 1/4–1/3 indehiscent, sides hirsute, hairs white, to 0.7 mm, sutures denticulate, hairs to 0.1 mm; staminode 15–18 mm, included, 0.4–0.5 mm diam., glabrous; style 19–23 mm. Capsules 8–13 × 5–8 mm. 2n = 16.
Phenology: Flowering Jun–Aug.
Habitat: Rocky ridges, peaks, open slopes in pine and fir forests.
Elevation: 1500–2400 m.
Penstemon purpusii is found in the North Coast and Klamath ranges. Populations have been documented in Colusa, Glenn, Humboldt, Lake, Mendocino, Shasta, Tehama, and Trinity counties.