Penstemon triphyllus

Subshrubs. Stems ascending to erect, 25–80 cm, retrorsely hairy, hairs pointed, not glaucous. Leaves cauline, whorled, sometimes alternate, glabrate or retrorsely hairy, hairs pointed, not glaucous; cauline 15–20 pairs, sessile, (5–) 10–52 × 1–6 (–12) mm, blade linear, sometimes lanceolate, base tapered, margins coarsely serrate-dentate, distals sometimes entire, apex acute. Thyrses interrupted, cylindric, 4–35 cm, axis glandular-pubescent, verticillasters 5–10, cymes 1–4-flowered, 1 or 2 (or 3) per node; proximal bracts linear, rarely lanceolate, 5–34 × 1–6 mm; peduncles and pedicels spreading to ascending, peduncles retrorsely hairy and, sometimes, glandular-pubescent distally, pedicels glandular-pubescent. Flowers: calyx lobes lanceolate, 3.5–5.8 × 1–2 mm, glandular-pubescent; corolla bluish lavender to lavender, pinkish, pale-purple, or violet, with reddish purple nectar guides, funnelform, 13–19 mm, glandular-pubescent externally, glabrous internally or sparsely white-lanate abaxially, tube 5–7 mm, throat gradually inflated, 5–6 mm diam., rounded abaxially; stamens included, filaments glabrous or white-pubescent distally, pollen-sacs parallel, 0.9–1.3 mm, distal 2/3 indehiscent, sides glabrous, sutures denticulate, teeth to 0.1 mm; staminode 9–11 mm, exserted, 0.2–0.3 mm diam., distal 6–7 mm moderately to densely lanate, hairs yellow, to 2.5 mm; style 8–10 mm. Capsules 4.5–7 × 3–4.5 mm. 2n = 16.

Phenology: Flowering May–Jul.
Habitat: Cliffs, rocky slopes, basalt.
Elevation: 300–1800 m.

Idaho, Oreg., Wash.

Discussion

Penstemon triphyllus occurs near the Snake River in northeastern Oregon (Baker and Wallowa counties), southeastern Washington (Asotin, Franklin, Garfield, Klickitat, Okanogan, and Whitman counties), and adjacent Idaho (Adams, Idaho, Lemhi, Lewis, Nez Perce, and Valley counties), extending up the Salmon River.

Selected References

None.

Lower Taxa