Penstemon laricifolius

Plants cespitose. Stems erect, 10–30 cm, glabrous or puberulent. Leaves basal and cauline, not leathery, glabrous, rarely puberulent proximally, especially along margins; basal and proximal cauline sessile, 15–20(–40) × 0.5–1.5 mm, blade linear, base tapered to ± clasping, margins entire, apex acute; cauline 3–7 pairs, sessile, 11–35 × 0.3–1 mm, blade linear, base tapered to ± clasping, margins entire, apex acute. Thyrses continuous or interrupted, cylindric, 3–15 cm, axis glabrous or retrorsely hairy, verticillasters 3–7, cymes 1- or 2(or 3)-flowered, 1 or 2 per node; proximal bracts linear, 10–30 × 0.3–1 mm; peduncles and pedicels glabrous, rarely puberulent. Flowers: calyx lobes ovate, 3.5–5.8 × 1.3–2.2 mm, glabrous; corolla white or pink to violet or purple, without nectar guides, tubular-funnelform, 9–18 mm, glabrous externally, moderately yellow-villous internally abaxially, tube 4–5 mm, throat gradually inflated, not constricted, 5–6 mm diam., rounded abaxially; stamens included, pollen sacs opposite, navicular, 1–1.5 mm, dehiscing completely, sutures papillate; staminode 7–11 mm, included or reaching orifice, 0.5–0.7 mm diam., tip straight to recurved, distal 3–5 mm pilose, hairs yellow or yellow-orange, to 1 mm; style 9–12 mm. Capsules 4–5 × 2.5–4 mm.

Distribution

w United States.

Discussion

Varieties 2 (2 in the flora).

Molecular data (A. D. Wolfe et al. 2006; C. A. Wessinger et al. 2016) place Penstemon laricifolius with or near sect. Cristati. Two varieties, differentiated by corolla color, are difficult to distinguish in the herbarium, where corollas are usually brown. Populations with a mix of white, pink, and purple corollas have been documented in Wyoming (B. L. Heidel and J. Handley 2007).

Selected References

None.

Lower Taxa

Penstemon laricifolius var. exilifolius, Penstemon laricifolius var. laricifolius

Key

1	Corollas pink to violet or purple, 10–18 mm; Montana, Wyoming.	Penstemon laricifolius var. laricifolius
1	Corollas white, 9–15 mm; Colorado, Wyoming.	Penstemon laricifolius var. exilifolius