Penstemon cyanocaulis
Bot. Gaz. 60: 380. 1915. (as Pentstemon)
Stems ascending to erect, (16–)20–60 cm, glabrous or ± puberulent proximally, ± glaucous. Leaves basal and cauline, ± leathery or not, glabrous or proximals puberulent proximally or along midveins, ± glaucous; basal and proximal cauline (30–)50–95 × 10–15(–28) mm, blade spatulate to oblanceolate, base tapered, margins entire, usually undulate, apex rounded to obtuse; cauline 2–4 pairs, sessile, 20–73 × 4–15 mm, blade lanceolate to elliptic, base truncate to clasping, margins crisped or undulate, apex acute. Thyrses interrupted, secund to subsecund, (4–)8–31 cm, axis glabrous, verticillasters 5–9(–12), cymes (1 or)2–5-flowered, 2 per node; proximal bracts ovate to lanceolate, 15–50 × 3–23 mm; peduncles and pedicels glabrous, peduncles to 18 mm, pedicels 1–7 mm. Flowers: calyx lobes ovate, 3.5–4.5 × 1.4–2 mm, apex acute to acuminate, glabrous; corolla blue to violet, with violet nectar guides, funnelform to weakly ventricose, 14–18(–20) mm, glabrous or ± glandular externally, glabrous internally, tube 5–8 mm, throat gradually inflated, not constricted at orifice, 5–7 mm diam., rounded abaxially; stamens: longer pair reaching orifice, pollen sacs divergent, navicular-sigmoid, 1.2–1.7 mm, dehiscing incompletely, proximal 1/4 indehiscent, connective not splitting, sides sparsely to moderately pilose, hairs white, to 0.5(–0.7) mm, sutures denticulate, teeth to 0.1 mm; staminode: 9–11 mm, reaching orifice, 0.2–0.4 mm diam., tip straight, distal 2–6 mm sparsely pilose, hairs golden yellow, to 0.6 mm; style 9–12 mm. Capsules 6–10 × 4–5 mm.
Phenology: Flowering Apr–Jun.
Habitat: Rocky slopes, pinyon-juniper, oak, and oak-juniper woodlands.
Elevation: 1300–2700 m.
Discussion
Penstemon cyanocaulis is known from Mesa, Montrose, and San Miguel counties, Colorado, and Carbon, Emery, Grand, and San Juan counties, Utah. It has crisped or undulate leaf margins that help distinguish it in the field.
Selected References
None.