Edinburgh New Philos. J. 7: 348. 1829. (as Pentstemon procerum)
Herbs. Stems ascending to erect, 3–55(–70) cm, glabrous or ± retrorsely hairy, not glaucous. Leaves basal and cauline, basal sometimes poorly developed, ± leathery or not, glabrous, puberulent, or retrorsely hairy; basal and proximal cauline 9–90(–115) × 2–19 mm, blade spatulate to oblanceolate, lanceolate, or elliptic, base tapered, margins entire, apex rounded to obtuse or acute; cauline 2–6 pairs, sessile or proximals sometimes short-petiolate, 6–85 × 1–17 mm, blade oblanceolate to spatulate, obovate, oblong, elliptic, lanceolate, or linear, base tapered to clasping, margins entire, apex rounded to obtuse or acute. Thyrses interrupted, cylindric, 0.5–23 cm, axis glabrous or retrorsely hairy, verticillasters 1–8(–11), cymes 3–11-flowered, 2 per node; proximal bracts lanceolate to linear, 10–50(–60) × 1–8(–16) mm, margins entire; peduncles and pedicels erect, glabrous, puberulent, or retrorsely hairy. Flowers: calyx lobes ovate to obovate or lanceolate, 1.2–5(–5.5) × 0.5–2 mm, apex truncate, obtuse, acute, acuminate, cuspidate, caudate, or mucronate, glabrous or puberulent to retrorsely hairy; corolla violet to blue or purple, with, sometimes without, reddish purple nectar guides, funnelform, 7–11 mm, glabrous externally, moderately white- or yellow-lanate internally abaxially, tube 2–3 mm, throat slightly inflated, 2–3 mm diam., 2-ridged abaxially; stamens included, pollen sacs opposite, explanate, 0.3–0.6 mm, dehiscing completely, connective splitting, sides glabrous, sutures smooth or papillate; staminode 4–6 mm, included, 0.2–0.3 mm diam., tip straight to slightly recurved, distal 0.5–1 mm pilose, hairs yellow or golden yellow, to 0.6 mm, rarely glabrous; style 4–7 mm. Capsules 3–5 × 2–4 mm, glabrous.
Alta., B.C., Man., Sask., Yukon, Alaska, Calif., Colo., Idaho, Mont., N.Dak., Nev., Oreg., Utah, Wash., Wyo.
Varieties 6 (6 in the flora).
Penstemon procerus is a widespread, frequent, and highly variable species distributed throughout much of western North America. This variability has resulted in varied interpretations of its taxonomic units.
|1||Calyx lobes (2–)3–5(–5.5) mm, apices acuminate, cuspidate, or short- to long-caudate.||> 2|
|2||Verticillasters (1–)3–8(–11); stems (6–)15–55(–70) cm; thyrses (1–)5–23 cm.||Penstemon procerus var. procerus|
|2||Verticillasters 1 or 2(–5); stems 3–20(–28) cm; thyrses 1–5(–13) cm.||Penstemon procerus var. tolmiei|
|1||Calyx lobes 1.2–3.2 mm, apices truncate to obtuse, acute, acuminate, mucronate, or short-caudate.||> 3|
|3||Verticillasters 1 or 2(–5); stems 3–15(–20) cm; cauline leaves 1–4(–8) mm wide.||Penstemon procerus var. formosus|
|3||Verticillasters (1 or)2–6; stems (4–)8–35(–42) cm; cauline leaves 2–13 mm wide.||> 4|
|4||Calyx lobes 1.2–2.4 mm, apices truncate to obtuse or mucronate, rarely short-caudate or acute; Nevada.||Penstemon procerus var. modestus|
|4||Calyx lobes (1.4–)1.8–3.2 mm, apices acute to acuminate or short-caudate; California, Oregon, Utah.||> 5|
|5||Pollen sacs 0.3–0.4 mm; corollas 7–10 mm; stems 10–35(–42) cm; Utah.||Penstemon procerus var. aberrans|
|5||Pollen sacs 0.4–0.6 mm; corollas 9–12 mm; stems 9–20(–30) cm; California, Oregon.||Penstemon procerus var. brachyanthus|