Penstemon filiformis

(D. D. Keck) D. D. Keck

in L. Abrams and R. S. Ferris, Ill. Fl. Pacific States 3: 761. 1951.

Common names: Thread-leaf beardtongue
Endemic
Basionym: Penstemon laetus subsp. filiformis D. D. Keck Univ. Calif. Publ. Bot. 16: 394. 1932
Treatment appears in FNA Volume 17. Treatment on page 233. Mentioned on page 231.

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.

Lower Taxa

None.
... more about "Penstemon filiformis"
Craig C. Freeman +
(D. D. Keck) D. D. Keck +
Penstemon laetus subsp. filiformis +
Thread-leaf beardtongue +
400–600 m. +
Rocky shrublands, pine woodlands. +
Flowering Jun–Jul. +
in L. Abrams and R. S. Ferris, Ill. Fl. Pacific States +
Penstemon subg. Saccanthera +
Penstemon filiformis +
Penstemon sect. Saccanthera +
species +