Penstemon filiformis
in L. Abrams and R. S. Ferris, Ill. Fl. Pacific States 3: 761. 1951.
Herbs or subshrubs. Stems ascending to erect, 16–50 cm, puberulent to retrorsely hairy, hairs pointed, not glaucous. Leaves cauline, opposite, puberulent, hairs pointed, or glabrous, not glaucous; cauline 8–12 pairs, sessile, 12–70 × 0.5–1(–2) mm, blade linear, base not tapered, margins entire, apex acute. Thyrses interrupted, cylindric, 9–22 cm, axis glandular-pubescent, verticillasters 1–5, cymes 1–3-flowered, (1 or)2 per node; proximal bracts linear, 9–30 × 0.5–1 mm; peduncles and pedicels spreading to ascending, glandular-pubescent. Flowers: calyx lobes ovate to lanceolate, 2–4.5 × 0.7–1.7 mm, glandular-pubescent; corolla light purple to violet or purple, without nectar guides, funnelform, 13–18 mm, glandular-pubescent externally, glabrous internally, tube 3–4 mm, throat gradually inflated, 5–7 mm diam., 2-ridged abaxially; stamens included or longer pair reaching orifice, filaments glabrous, pollen sacs parallel, 1.2–1.6 mm, distal 1/2 indehiscent, sides pubescent, hairs white, to 0.5 mm near filament attachment, sutures denticulate, teeth to 0.2 mm; staminode 10–12 mm, included or reaching orifice, 0.3–0.5 mm diam., glabrous; style 11–15 mm. Capsules 5–7.5 × 2.5–4 mm. 2n = 16.
Phenology: Flowering Jun–Jul.
Habitat: Rocky shrublands, pine woodlands.
Elevation: 400–600 m.
Discussion
Penstemon filiformis is known from Lake, Shasta, Siskiyou, and Trinity counties.
Selected References
None.