Penstemon gibbensii

Stems ascending to erect, 10–37 cm, pubescent to retrorsely hairy, sometimes glabrous proximally, glandular-pubescent distally, not glaucous. Leaves basal and cauline, or basal absent or reduced, not leathery, proximals glabrous or puberulent to scabrous, distals puberulent or scabrous to glandular-pubescent, not glaucous; basal and proximal cauline 15–90 × 2–7(–8) mm, blade oblanceolate to linear, base tapered, margins entire, apex obtuse to acute; cauline 6–10 pairs, short-petiolate or sessile, 9–68 × 1–5 mm, blade oblanceolate to linear, base tapered to truncate, apex obtuse to acute. Thyrses interrupted, secund, (2–)5–14 cm, axis glandular-pubescent, verticillasters (2–)5–8, cymes 1–3-flowered, 1 or 2 per node; proximal bracts lanceolate, proximals 8–43 × 1–3 mm; peduncles and pedicels glandular-pubescent. Flowers: calyx lobes ovate to lanceolate, 3.5–7(–8) × 1.8–2.5 mm, glandular-pubescent; corolla lavender to light blue or light violet, with faint reddish purple nectar guides, funnelform, (15–)16–18(–20) mm, glandular-pubescent externally, sparsely to moderately glandular-pubescent or glandular internally abaxially, tube 5.5–6.5 mm, throat gradually inflated, not constricted at orifice, 5–6 mm diam., rounded abaxially; stamens: longer pair reaching orifice, pollen sacs divergent, navicular, 1–1.4 mm, dehiscing incompletely, proximal 1/5 indehiscent, connective not splitting, sides moderately hirsute, hairs white, to 0.7 mm, sutures denticulate, teeth to 0.1 mm; staminode 8–10 mm, included, 0.6–0.7 mm diam., tip recurved, distal 1–3 mm sparsely pilose or lanate, hairs yellow or whitish, to 1 mm; style 11–16 mm. Capsules 5–8 × 3.5–5 mm.

Phenology: Flowering Jun–Sep.
Habitat: Barren hills, pinyon-juniper woodlands, sagebrush and greasewood-saltbush shrublands.
Elevation: 1700–2300 m.

Colo., Utah, Wyo.

Discussion

Penstemon gibbensii is known from fewer than ten populations in Moffat and Rio Blanco counties, Colorado, Daggett County, Utah, and Carbon and Sweetwater counties, Wyoming (S. L. O’Kane 1988; E. C. Neese and N. D. Atwood 2003). Plants occur on shales or sandstones of the Browns Park Formation and Green River Formation (B. L. Heidel 2009).

Selected References

None.

Lower Taxa