Penstemon scariosus
Contr. U.S. Natl. Herb. 20: 353. 1920.
Stems ascending or erect, rarely decumbent, (8–)16–50(–60) cm, glabrous, not glaucous. Leaves basal and cauline, or basal not persisting, ± leathery or not, glabrous, not glaucous; basal and proximal cauline (18–)35–180 × (3–)6–15(–24) mm, blade oblanceolate to oblong or linear, base tapered, margins entire, apex obtuse to acute; cauline 3–5(or 6) pairs, sessile or proximals sometimes short-petiolate, 34–115 × 2–14 mm, blade oblanceolate to oblong or linear, base tapered, apex obtuse to acute. Thyrses interrupted or continuous, secund, (1–)6–18(–25) cm, axis glabrous or sparsely glandular-pubescent, verticillasters (2 or)3–7(–9), cymes (1 or)2–5-flowered, 2 per node; proximal bracts lanceolate to linear, 25–70(–95) × (1–)3–12(–20) mm; peduncles and pedicels glabrous or glandular-pubescent. Flowers: calyx lobes ovate to lanceolate, (4–)4.8–11 × 1.3–3.2(–3.7) mm, glabrous or glandular-pubescent; corolla blue to lavender, with reddish purple nectar guides, ventricose, 18–33 mm, sparsely to moderately glandular-pubescent externally, glabrous, rarely sparsely white-villous, internally abaxially, tube 6–11 mm, throat gradually inflated, slightly constricted at orifice, 6–11 mm diam., rounded abaxially; stamens: longer pair reaching orifice, pollen sacs divergent to opposite, navicular to navicular-sigmoid, (1.3–)1.5–2.4 mm, dehiscing incompletely, proximal 1/5 indehiscent, connective not splitting, sides moderately pubescent, hairs white, to 0.8 mm, sutures denticulate, teeth to 0.1 mm; staminode 11–19 mm, reaching orifice, 0.3–0.8 mm diam., tip straight to recurved, distal 3–7 mm sparsely to moderately villous, hairs yellow, to 0.8 mm; style 12–22 mm. Capsules 6–10 × 5–6.5 mm.
Distribution
Colo., Utah, Wyo.
Discussion
Varieties 4 (4 in the flora).
Penstemon scariosus comprises four varieties centered in the northwestern Colorado Plateau, Uinta Basin, and Wasatch Range.
Selected References
None.
Lower Taxa
Key
| 1 | Corollas 25–33 mm; calyx lobes 7–11 mm; pollen sacs 1.8–2.4 mm. | Penstemon scariosus var. scariosus |
| 1 | Corollas 18–28 mm; calyx lobes (4–)4.8–8 mm; pollen sacs (1.3–)1.5–2.2 mm. | > 2 |
| 2 | Corollas sparsely to moderately glandular-pubescent externally, limbs blue to bluish purple; styles 12–14 mm. | Penstemon scariosus var. cyanomontanus |
| 2 | Corollas sparsely glandular-pubescent externally, limbs lavender to pale blue or blue; styles 13–22 mm. | > 3 |
| 3 | Corolla limbs lavender to pale blue; styles 18–22 mm; basal leaves seldom persisting. | Penstemon scariosus var. albifluvis |
| 3 | Corolla limbs blue; styles 13–17 mm; basal leaves usually persisting. | Penstemon scariosus var. garrettii |