Penstemon wilcoxii


Bull. Torrey Bot. Club 28: 28. 1901. (as Pentstemon)

Common names: Wilcox’s beardtongue
Synonyms: Penstemon ovatus var. pinetorum Piper
Treatment appears in FNA Volume 17. Treatment on page 227. Mentioned on page 187, 189, 190, 194, 214, 228.

Herbs. Stems ascending to erect, (20–)35–100 cm, glabrous or sparsely to densely puberulent, sometimes also sparsely glandular-pubescent, especially distally, not glaucous. Leaves basal and cauline, ± leathery or not, glabrous or puberulent to pubescent, especially along midveins; basal and proximal cauline (25–)35–190 × (5–)12–55 mm, blade triangular to ovate or lanceolate, base tapered, rarely truncate, margins ± serrate or dentate, apex acute, rarely obtuse; cauline 2–5 pairs, short-petiolate or sessile, 35–90 × (8–)15–50 mm, blade ovate to oblong or lanceolate, base tapered to clasping or cordate-clasping, margins serrate to dentate, apex obtuse to acute. Thyrses interrupted, cylindric to conic, (5–)8–30 cm, axis sparsely to moderately glandular-pubescent, verticillasters 3–7, cymes 3–11-flowered, 2 per node; proximal bracts ovate to lanceolate, (8–)18–75 × (5–)8–35 mm, margins ± serrate to dentate; peduncles and pedicels spreading to ascending, ± glandular-pubescent. Flowers: calyx lobes ovate, 2.4–5.5 × 0.9–1.8 mm, margins broadly scarious, glandular-pubescent; corolla blue to violet or light blue, with reddish purple nectar guides, funnelform, 13–23 mm, glandular-pubescent externally, sparsely white- or yellow-villous internally abaxially, tube 4–8 mm, throat gradually inflated, 4–9 mm diam., 2-ridged abaxially; stamens included, pollen sacs opposite, navicular to subexplanate, 0.8–1 mm, dehiscing completely, connective splitting, sides glabrous, sutures smooth or ± papillate; staminode 8–11 mm, reaching orifice, 0.2–0.3 mm diam., tip straight to recurved, distal 1–5 mm pilose to villous, hairs yellow, to 1.2 mm; style 9–13 mm. Capsules 4–6.5 × 3–4 mm, glabrous. 2n = 16, 32.

Phenology: Flowering May–Aug.
Habitat: Rocky or gravelly slopes in forests and woodlands, roadcuts.
Elevation: 300–2300 m.


Idaho, Mont., Oreg., Wash.


Penstemon wilcoxii hybridizes with P. albertinus in areas of sympatry in east-central Idaho and west-central Montana (D. D. Keck 1945; A. Cronquist 1959; D. V. Clark 1971). Putative hybrids and/or introgressants exhibit varying degrees of morphologic intermediacy between the parent species. Many herbarium specimens are difficult to determine with confidence.

Selected References


Lower Taxa

... more about "Penstemon wilcoxii"
Craig C. Freeman +
Rydberg +
Wilcox’s beardtongue +
Idaho +, Mont. +, Oreg. +  and Wash. +
300–2300 m. +
Rocky or gravelly slopes in forests and woodlands, roadcuts. +
Flowering May–Aug. +
Bull. Torrey Bot. Club +
Penstemon ovatus var. pinetorum +
Penstemon wilcoxii +
Penstemon sect. Penstemon +
species +