Penstemon comarrhenus
Proc. Amer. Acad. Arts 12: 81. 1876. (as Pentstemon)
Stems ascending to erect, (18–)40–80(–120) cm, glabrous, sometimes retrorsely hairy proximally, not glaucous. Leaves basal and cauline, ± leathery or not, glabrous or sparsely retrorsely hairy, rarely densely retrorsely hairy, not glaucous; basal and proximal cauline 40–80(–120) × 7–20(–30) mm, blade obovate to oblanceolate, base tapered, margins entire, apex obtuse to acute; cauline 5–7(or 8) pairs, sessile, 38–110 × 1–10 mm, blade oblanceolate to linear, base tapered, apex obtuse to acute. Thyrses erupted, secund, sometimes subsecund, (12–)15–32 cm, axis glabrous, verticillasters 6–12, cymes 1–2(–5)-flowered, 2 per node; proximal bracts linear, (6–)26–84 × 1–4 mm; peduncles and pedicels glabrous. Flowers: calyx lobes ovate, (2.2–)3.5–6(–7) × 2.1–2.7 mm, glabrous; corolla blue to pinkish blue or lavender, with violet nectar guides, ventricose, 25–35(–38) mm, glabrous externally, glabrous internally, tube 8–11(–14) mm, throat abruptly inflated, slightly constricted at orifice, 9–13 mm diam., slightly 2-ridged abaxially; stamens: longer pair exserted, pollen sacs divergent to nearly opposite, navicular-sigmoid, 2–2.5(–2.8) mm, dehiscing incompletely, proximal 1/5 indehiscent, connective not splitting, sides densely villous or lanate, hairs white, to 2.5 mm, sutures smooth, papillate, or denticulate, teeth to 0.1 mm; staminode 12–17 mm, included, 0.8–1 mm diam., tip straight, glabrous or distal 1–2 mm sparsely pilose, hairs white, to 0.5 mm; style 16–25 mm. Capsules (7–)10–15 × 4–5 mm.
Phenology: Flowering Jun–Aug.
Habitat: Pinyon-juniper, Gambel oak, and ponderosa pine woodlands.
Elevation: (1000–)1600–2800 m.
Distribution
Ariz., Colo., Nev., N.Mex., Utah.
Discussion
Penstemon comarrhenus usually is distinguished from P. strictus by its paler blue corollas, more diffuse inflorescences, and more densely lanate anthers. A putative hybrid between P. comarrhenus and P. barbatus var. trichander has been collected in La Plata County, Colorado (R. E. Umber, B. E. Nelson & T. Davis 999b, KANU, RM).
Selected References
None.