Penstemon globosus

Herbs. Stems ascending to erect, (10–)20–65 cm, glabrous or sparsely retrorsely hairy distally, not glaucous. Leaves basal and cauline, not leathery, glabrous; basal and proximal cauline 28–160(–235) × 8–25(–35) mm, blade oblanceolate to elliptic, base tapered, margins entire, apex obtuse to acute; cauline 2–5 pairs, sessile or proximals short-petiolate, 10–130 × 3–35 mm, blade oblong to ovate or lanceolate, base truncate to clasping, margins entire, apex obtuse to acute. Thyrses continuous or interrupted, cylindric, (1–)2–11(–27) cm, axis glabrous or sparsely retrorsely hairy, verticillasters 1–3(or 4), cymes (2–)4–13-flowered, 2 per node; proximal bracts lanceolate, (5–)16–66 × (1–)4–19 mm, margins entire; peduncles and pedicels erect, glabrous. Flowers: calyx lobes oblanceolate to lanceolate, (4–)5–9 × 1.4–3.5 mm, glabrous; corolla blue to purple or violet, without nectar guides, tubular-funnelform, 14–21 mm, glabrous externally, moderately white- or yellowish pilose internally abaxially, tube 5–6 mm, throat slightly inflated to slightly ventricose, 4–7 mm diam., 2-ridged abaxially; stamens included, pollen sacs divergent, saccate, 0.7–1.2 mm, dehiscing incompletely, distal 1/5–1/4 indehiscent, connective not splitting, sides glabrous, sutures papillate; staminode 7–9 mm, included, 0.4–0.7 mm diam., tip straight to slightly recurved, distal 1–2 mm densely pilose to lanate, hairs golden yellow, to 1.4 mm, medial 2–4 mm sparsely lanate; style 8–10 mm. Capsules 5–7 × 3–4 mm, glabrous. 2n = 16, 32.

Phenology: Flowering May–Aug.
Habitat: Dry to wet meadows, moist mountain slopes.
Elevation: 800–3100 m.

Idaho, Mont., Oreg.

Discussion

The saccate anthers and relatively broad leaves of Penstemon globosus are diagnostic. D. V. Clark (1971) reported plants in northeastern Oregon (Baker, Union, and Wallowa counties) exhibiting degrees of morphologic intermediacy between P. globosus and P. rydbergii. These could be hybrids or introgressants involving those two species, though Clark did not observe any populations where hybridization was evident. Putative hybrids between P. globosus and P. confertus have been documented in Idaho County, Idaho (Clark).

Selected References

None.

Lower Taxa