Penstemon angustifolius
Fl. Amer. Sept. 2: 738. 1813.
Stems ascending to erect, (6–) 15–45 (–65) cm, glabrous or scabrous. Leaves basal and cauline, basal not reduced, glabrous, sometimes scabrous; basal and proximal cauline (25–) 40–90 × 2–18 mm, blade spatulate to oblanceolate or linear, base tapered, apex rounded to obtuse or acute; cauline 2–8 pairs, sessile, 18–113 × 2–24 (–40) mm, blade ovate to lanceolate or linear, base tapered to cordate-clasping, apex acute to acuminate. Thyrses continuous or interrupted, cylindric, (2–) 5–30 (–37) cm, axis glabrous, rarely scabrous, verticillasters (3–) 5–15 (–26), cymes (2–) 4–8 (–10) -flowered; proximal bracts ovate to lanceolate or linear, (3–) 12–98 × (1–) 2–28 mm; peduncles and pedicels glabrous or scabrous, peduncles to 3 mm. Flowers: calyx lobes ovate to lanceolate, 4–8 × 1–2.5 mm, margins entire or erose, broadly scarious, glabrous or scabrous; corolla lavender, blue, or pink, with violet or reddish purple nectar guides, tubular-funnelform, 13–20 (–22) mm, glabrous externally, sparsely white-pubescent internally abaxially or glabrous, tube 6–8 mm, throat gradually inflated, 4–6 mm diam., rounded abaxially; stamens included or longer pair reaching orifice, pollen-sacs opposite, (0.9–) 1.1–1.5 mm, sutures papillate; staminode 8–10 mm, reaching orifice, 0.9–1.2 mm diam., tip recurved, distal 4–6 mm sparsely villous, hairs golden yellow, to 1 mm, hairs on proximal part of staminode mostly along margins; style 8–12 mm. Capsules 9–15 × 5–7 mm.
Distribution
Ariz., Colo., Kans., Mont., N.Dak., N.Mex., Nebr., Okla., S.Dak., Utah, Wyo.
Discussion
Varieties 5 (5 in the flora).
Penstemon angustifolius comprises five varieties: two widespread in the west-central Great Plains and three with more limited, allopatric ranges.
Selected References
None.
Lower Taxa
Key
| 1 | Corollas pink; cauline leaf blades lanceolate to linear; Juab and Millard counties, Utah. | Penstemon angustifolius var. dulcis |
| 1 | Corollas blue or lavender, rarely pink; cauline leaf blades ovate to lanceolate or linear (if corollas pink, leaf blades broader or plants not of Juab or Millard counties, Utah); Arizona, Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Utah, Wyoming. | > 2 |
| 2 | Cauline leaf blades and proximal bracts lanceolate to linear. | > 3 |
| 3 | Stems glabrous or scabrous; corollas 14–18 mm; cauline leaves 2–5(or 6) pairs; stems (6–)10–30 cm; Colorado, Montana, Nebraska, North Dakota, South Dakota, Wyoming. | Penstemon angustifolius var. angustifolius |
| 3 | Stems glabrous, rarely scabrous; corollas (14–)18–20(–22) mm; cauline leaves 4–7 pairs; stems (8–)15–45 cm; Colorado, Utah. | Penstemon angustifolius var. vernalensis |
| 2 | Cauline leaf blades and proximal bracts ovate to lanceolate. | > 4 |
| 4 | Corollas 13–20(–22) mm, blue, rarely lavender or pink; Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Wyoming. | Penstemon angustifolius var. caudatus |
| 4 | Corollas 14–17 mm, blue to lavender or pink; Arizona, Colorado, New Mexico, Utah. | Penstemon angustifolius var. venosus |
"/4+timescorollathroat" is not declared as a valid unit of measurement for this property.