Penstemon attenuatus

Douglas ex Lindley

Edwards’s Bot. Reg. 15: plate 1295. 1830. (as Pentstemon attenuatum)

Common names: Taper-leaf beardtongue
Treatment appears in FNA Volume 17. Treatment on page 193. Mentioned on page 189, 190, 194, 204.

Herbs. Stems ascending to erect, (2–)5–70(–90) cm, glabrous or retrorsely hairy, not glaucous. Leaves basal and cauline, not leathery, glabrous or puberulent; basal and proximal cauline (30–)55–90(–150) × 5–20(–40) mm, blade spatulate to obovate or elliptic, base tapered, margins entire, rarely denticulate, apex rounded to obtuse or acute; cauline 2–5(–7) pairs, sessile or proximals short- to long-petiolate, 15–90(–130) × 2–25(–38) mm, blade usually lanceolate, proximals sometimes oblanceolate, base tapered to clasping, margins entire, rarely serrate or dentate, apex acute, sometimes obtuse. Thyrses interrupted, cylindric, 3–27 cm, axis moderately glandular-pubescent, verticillasters 2–7, cymes (1 or)2–8-flowered, 2 per node; proximal bracts lanceolate, 15–55(–80) × 2–15(–28) mm, margins entire or ± serrate to dentate; peduncles and pedicels erect, glandular-pubescent. Flowers: calyx lobes ovate to obovate, ovate-oblong, or lanceolate, 3.2–7.5 × 0.9–2.6 mm, margins erose or lacerate, apex acuminate to short-caudate or long-acuminate, glandular-pubescent; corolla light blue to violet, bluish purple, or pinkish blue, rarely light yellow or whitish, with reddish purple nectar guides, tubular-funnelform, 7–20 mm, glandular-pubescent externally, moderately white-lanate internally abaxially, tube 4–5 mm, throat slightly inflated, 3–5(–6) mm diam., 2-ridged abaxially; stamens included, pollen sacs opposite, navicular to slightly saccate, 0.6–1.2 mm, dehiscing completely or incompletely, distal 1/5 or less sometimes indehiscent, connective splitting or not, sides glabrous, sutures smooth or papillate; staminode 7–9 mm, reaching orifice or slightly exserted, 0.3–0.4 mm diam., tip straight to slightly recurved, distal 1–3 mm ± pilose, hairs yellow, to 1.2 mm; style 8–12 mm. Capsules 4–8 × 2–5 mm, glabrous. 2n = 48.


Idaho, Mont., Oreg., Wash., Wyo.


Varieties 4 (4 in the flora).

Selected References



1 Pollen sacs dehiscing incompletely, distal 1/5 or less usually indehiscent, connectives not splitting, sutures papillate. Penstemon attenuatus var. militaris
1 Pollen sacs dehiscing completely, connectives splitting, sutures smooth, sometimes ± papillate. > 2
2 Corollas 7–12 mm; calyx lobes lanceolate. Penstemon attenuatus var. palustris
2 Corollas 12–20 mm; calyx lobes ovate, obovate, ovate-oblong, or lanceolate. > 3
3 Stems (22–)30–70(–90) cm; corollas light blue to violet, rarely light yellow or whitish, 14–20 mm; calyx lobe margins erose. Penstemon attenuatus var. attenuatus
3 Stems (2–)5–40 cm; corollas bluish purple, 12–16 mm; calyx lobe margins erose or lacerate. Penstemon attenuatus var. pseudoprocerus