Penstemon davidsonii

Greene

Pittonia 2: 241. 1892. (as Pentstemon)

Common names: Davidson’s beardtongue
Endemic
Synonyms: Penstemon menziesii subsp. davidsonii (Greene) Piper
Treatment appears in FNA Volume 17. Treatment on page 87. Mentioned on page 86.

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.

Distribution

B.C., Calif., Nev., Oreg., Wash.

Discussion

Varieties 3 (3 in the flora).

Penstemon davidsonii occurs mostly at high elevations in the Cascade Range and Sierra Nevada.

Selected References

None.

Key

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