Penstemon eriantherus
Fl. Amer. Sept. 2: 737. 1813.
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
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 |