Penstemon retrorsus

Stems ascending to erect, 10–20 cm, retrorsely hairy, hairs pointed. Leaves not leathery, retrorsely hairy, hairs pointed; basal and proximal cauline 5–21 × 1–4 mm, blade spatulate to oblanceolate, base tapered, apex rounded to obtuse; cauline 2–4 pairs, petiolate or sessile, 8–30 × 2–5 mm, blade spatulate to oblanceolate, base tapered, apex rounded to obtuse, acute, or mucronate. Thyrses continuous, cylindric, 3–12 cm, axis retrorsely hairy, hairs pointed, verticillasters 4–12, cymes 1–4-flowered, 1 or 2 per node; proximal bracts oblanceolate, 11–22 × 2–3 mm; peduncles and pedicels ascending to erect, retrorsely hairy, hairs pointed. Flowers: calyx-tube 1.5–2 mm, lobes lanceolate to oblong, 3.5–4.5 × 0.7–1.2 mm, herbaceous or narrowly scarious-margined, retrorsely hairy, hairs pointed; corolla bluish violet, lined internally abaxially with reddish violet nectar guides, tubular-funnelform, 16–20 mm, sparsely white-lanate internally abaxially, tube 6–7 mm, throat gradually inflated, 4.5–6 mm diam., 2-ridged abaxially; stamens included, filaments glabrous, pollen-sacs opposite, subexplanate, 0.7–0.9 mm, sutures papillate; staminode 7–9 mm, included or reaching orifice, flattened distally, 0.2–0.3 mm diam., tip recurved, distal 4–6 mm pubescent, hairs yellowish orange, to 0.8 mm; style 12–15 mm. Capsules not seen.

Phenology: Flowering May–Jun.
Habitat: Clay soils, sagebrush, saltbush shrublands, pinyon-juniper woodlands.
Elevation: 1500–2500 m.

Colo.

Discussion

Penstemon retrorsus is known only from Delta and Montrose counties, where populations occur on barren hills of the Mancos Shale. It is unique in having calyx tubes roughly as long as the calyx lobes.

Selected References

None.

Lower Taxa