Penstemon attenuatus var. attenuatus
Stems (22–)30–70(–90) cm. Flowers: calyx lobes ovate to obovate or lanceolate, margins erose; corolla light blue to violet, rarely light yellow or whitish, 14–20 mm; pollen sacs 0.8–1.2 mm, dehiscing completely, connective splitting, sutures smooth, sometimes ± papillate. 2n = 48.
Phenology: Flowering May–Aug.
Habitat: Gravelly or rocky clearings in pine forests, clearcut slopes, montane meadows.
Elevation: 500–2300 m.
Distribution
Idaho, Mont., Oreg., Wash.
Discussion
Some specimens of var. attenuatus from Idaho County, Idaho, have relatively large cauline leaves with serrate to dentate margins as in Penstemon wilcoxii. They generally have shorter, more erect peduncles than are typical of P. wilcoxii. Also, the glandular hairs of the thyrse axes and corollas tend to be longer and stouter than in P. wilcoxii. Penstemon nelsoniae, which has relatively large, yellow corollas, is known only from two collections in Clallam County, Washington. It was evidently a garden adventive or originated from seeds that were sown intentionally. Forms of var. attenuatus with whitish or yellowish corollas occur in Idaho, Oregon, and Washington, sometimes in pure stands and sometimes in mixed stands with blue-flowered forms (D. D. Keck 1945). These plants (which have glandular-pubescent inflorescences and pollen sacs 0.9–1.1 mm) from northeastern Oregon could be the source of reports of P. flavescens from that state.
Selected References
None.