Penstemon eriantherus

Stems ascending to erect, (2–)6–60 cm, retrorsely hairy, sometimes also villous or glandular-villous, or glabrate. Leaves basal and cauline, not leathery, glabrous or glabrate to retrorsely hairy and, sometimes, sparsely villous abaxially, glabrous or glabrate to retrorsely hairy and, sometimes, villous or glandular-villous adaxially; basal and proximal cauline petiolate, (14–)22–130(–180) × 3–30(–40) mm, blade spatulate to obovate, oblanceolate, elliptic, or linear, base tapered, margins entire or ± dentate to serrate, apex rounded to obtuse or acute; cauline 2–6 pairs, sessile or proximals short-petiolate, 18–90 × 3–20(–25) mm, blade oblanceolate to oblong, lanceolate, or linear, base tapered to clasping or cordate-clasping, margins entire or ± dentate to serrate, apex obtuse to acute. Thyrses continuous or interrupted, cylindric, (1–)2–20(–27) cm, axis glandular-pubescent to glandular-villous, sometimes also retrorsely hairy, verticillasters 2–7(–9), cymes (1 or)2–6-flowered, 2 per node; proximal bracts oblanceolate to oblong or lanceolate, 12–75 × 2–23 mm; peduncles and pedicels glandular-villous or glandular-pubescent and, sometimes, also retrorsely hairy. Flowers: calyx lobes lanceolate, 5.5–13 × 1.4–3 mm, glandular-pubescent to glandular-villous; corolla lavender to violet, purple, pink, or blue, with reddish purple nectar guides, funnelform or ventricose-ampliate, 16–35(–42) mm, sparsely to densely white- or yellow-villous internally abaxially, sometimes glandular-pubescent laterally, tube 4–9 mm, throat gradually to abruptly inflated, constricted or not at orifice, 6–14 mm diam., rounded abaxially; stamens included, pollen sacs widely divergent to opposite, navicular to subexplanate or explanate, 0.8–1.9 mm, dehiscing completely, sutures smooth or papillate; staminode 12–18 mm, exserted or prominently exserted, 0.3–0.9 mm diam., tip recurved, distal 6–15 mm sparsely to densely lanate, hairs yellow, yellowish, or orangish, to 4 mm, and medial hairs shorter, stiffer, and retrorse; style 9–20 mm, glabrous or proximal 1–10 mm sparsely glandular-pubescent. Capsules 6–13 × 4–6 mm, sparsely glandular-pubescent distally.

Distribution

w, c North America.

Discussion

Varieties 5 (5 in the flora).

D. D. Keck (1938) treated this complex as three species: Penstemon cleburnei, P. eriantherus (with three varieties), and P. whitedii (with three subspecies). Most authors followed A. Cronquist (1959), who employed a broader species concept; the approach by Cronquist is followed here.

Selected References

None.

Lower Taxa

Penstemon eriantherus var. argillosus, Penstemon eriantherus var. cleburnei, Penstemon eriantherus var. eriantherus, Penstemon eriantherus var. redactus, Penstemon eriantherus var. whitedii

Key

1	Corollas constricted at orifices; styles 9–12(–14) mm; pollen sacs 0.8–1.2 mm.	Penstemon eriantherus var. cleburnei
1	Corollas not constricted at orifices; styles 9–20 mm; pollen sacs 1–1.9 mm.	> 2
2	Stems glabrate or retrorsely hairy, rarely glandular-villous, proximally, glandular-villous distally; leaves glabrous or glabrate abaxially, glabrate or villous to glandular-villous adaxially.	Penstemon eriantherus var. whitedii
2	Stems retrorsely hairy and, sometimes, sparsely villous, glandular-villous, or glandular-pubescent distally; leaves retrorsely hairy and, sometimes, sparsely villous or glabrous abaxially, retrorsely hairy or puberulent and, sometimes, villous or glandular-villous adaxially.	> 3
3	Corollas funnelform; staminodes sparsely lanate distally; leaves glabrous abaxially.	Penstemon eriantherus var. argillosus
3	Corollas ventricose-ampliate; staminodes moderately to densely lanate distally; leaves retrorsely hairy, sparsely villous, or glabrous abaxially.	> 4
4	Pollen sacs explanate; stems retrorsely hairy and, usually, sparsely villous or glandular-villous distally; corollas (20–)22–35(–42) mm.	Penstemon eriantherus var. eriantherus
4	Pollen sacs navicular to subexplanate; stems retrorsely hairy, sometimes also glandular-pubescent distally or wholly; corollas 18–25 mm.	Penstemon eriantherus var. redactus