Pittonia 2: 241. 1892.
Subshrubs, cespitose. Stems ascending to erect, 4–10 (–17) cm, retrorsely hairy or puberulent, not glaucous. Leaves persistent, 5–10 pairs, distals usually distinctly smaller than proximals, short-petiolate or sessile, (5–) 10–20 (–30) × 4–11 mm, blade elliptic to orbiculate, ovate, or spatulate, base tapered, margins entire or serrulate, apex rounded to obtuse or acute, glabrous or obscurely puberulent, not glaucous. Thyrses continuous, ± secund, 1–6 cm, axis retrorsely hairy proximally, retrorsely hairy and glandular-pubescent distally, verticillasters (1 or) 2–7, cymes 1-flowered; proximal bracts round to ovate or lanceolate, 3–12 × 1–6 mm, margins entire; peduncles and pedicels ascending to erect, glandular-pubescent, sometimes also puberulent. Flowers: calyx lobes lanceolate to linear, 7–12 (–14) × 2.5–4.3 mm, glandular-pubescent; corolla lavender to bluish lavender, violet, or purple, essentially unlined internally but abaxial ridges usually lavender or white, nearly personate, funnelform, 20–45 mm, glabrous externally, sparsely to moderately white-villous internally abaxially, tube (4–) 6–12 mm, throat 7–12 mm diam.; stamens included, pollen-sacs 0.9–1.6 mm; staminode 7–14 mm, slightly flattened distally, 0.1–0.2 mm diam., tip straight, distal 4–7 mm sparsely to densely villous, hairs whitish, to 1 mm; style 19–26 mm. Capsules 8–13 × 5–8 mm.
B.C., Calif., Nev., Oreg., Wash.
Varieties 3 (3 in the flora).
Penstemon davidsonii occurs mostly at high elevations in the Cascade Range and Sierra Nevada.
|1||Corollas (30–)34–45 mm; leaf blades elliptic to ovate, sometimes spatulate, margins entire.||Penstemon davidsonii var. praeteritus|
|1||Corollas 20–36 mm; leaf blades spatulate to orbiculate or elliptic, margins serrulate or entire.||> 2|
|2||Leaf blade margins entire, sometimes serrulate, apices rounded to obtuse.||Penstemon davidsonii var. davidsonii|
|2||Leaf blade margins ± serrulate, apices rounded to obtuse or acute.||Penstemon davidsonii var. menziesii|
"/3-3/4timescorollathroat" is not declared as a valid unit of measurement for this property.