Penstemon sect. Erianthera

G. Don

Gen. Hist. 4: 639. 1837. (as Pentstemon)

Treatment appears in FNA Volume 17. Treatment on page 85. Mentioned on page 82.

Herbs, shrubs, or subshrubs. Stems glabrous or retrorsely hairy, sometimes glandular-pubescent distally, glaucous or not. Leaves cauline, opposite, rarely subopposite (P. lyallii), leathery, sometimes not (P. lyallii, P. personatus), glabrous or hairy, glaucous or not; cauline petiolate, short-petiolate, or sessile, blade round, orbiculate, ovate, obovate, lanceolate, oblanceolate, spatulate, elliptic, or oblong, rarely linear, margins entire or toothed. Thyrses continuous or interrupted, ± secund, rarely cylindric or conic, axis hairy, rarely glabrous, cymes 2 per node; peduncles and pedicels spreading or ascending to erect. Flowers: calyx lobes: margins entire or erose, ± scarious or herbaceous, glandular-pubescent, rarely glabrous or inconspicuously glandular; corolla lilac, lavender, blue, violet, purple, pink, red, scarlet, or white, bilaterally symmetric, strongly bilabiate, personate or not, funnelform, rarely tubular-funnelform, glabrous externally, rarely glandular-pubescent, hairy internally abaxially, rarely glabrous, throat gradually inflated, not constricted at orifice, 2-ridged abaxially; stamens included or longer pair exserted, filaments glabrous, pollen sacs opposite; staminode 0.1–0.4 mm diam., tip straight to recurved, glabrous or distal 10–50% hairy, hairs to 1.5 mm; style glabrous. Capsules glabrous. Seeds brown, 0.8–4 mm.


w North America.


Species 10 (10 in the flora).

Morphologic and molecular data support inclusion of Penstemon personatus in sect. Erianthera (A. D. Wolfe et al. 2006). D. D. Keck (1936b) placed P. personatus in sect. Cryptostemon D. D. Keck; that name is invalid, because it lacked a diagnosis.

Selected References



1 Pollen sac sides glabrous. Penstemon personatus
1 Pollen sac sides lanate. > 2
2 Thyrse axes glabrous. Penstemon barrettiae
2 Thyrse axes glandular-pubescent at least distally, sometimes also retrorsely hairy. > 3
3 Cymes 2–7-flowered; staminodes 10–13 mm; stems (18–)30–80 cm; leaves 8–13 pairs, blades lanceolate, rarely linear, 23–130 × 3–20 mm. Penstemon lyallii
3 Cymes 1-flowered; staminodes 7–16 mm; stems 3–40 cm; leaves 2–10 pairs, blades orbiculate, obovate, spatulate, oblanceolate, ovate, elliptic, broadly lanceolate, or round, 4–55(–60) × 3–17(–28) mm. > 4
4 Leaves: distals seldom distinctly smaller than proximals, all deciduous, sometimes persistent. > 5
5 Leaves glabrous, not glaucous; leaf blades obovate to ovate, elliptic, or lanceolate, margins ± crenulate-serrulate; thyrses cylindric to ± secund. Penstemon ellipticus
5 Leaves glabrous or puberulent, or puberulent and glandular-pubescent, glaucous or not; leaf blades obovate to oblanceolate, ovate, lanceolate, or elliptic, margins entire, subentire, serrate, or dentate; thyrses secund. Penstemon montanus
4 Leaves: distals usually distinctly smaller than proximals, all persistent. > 6
6 Leaf blades lanceolate to oblanceolate or elliptic, not glaucous. Penstemon fruticosus
6 Leaf blades round, elliptic, obovate, ovate, orbiculate, or spatulate, glaucous or not. > 7
7 Corollas blue, lavender, violet, or purple; leaves ± or not glaucous; stamens included. > 8
8 Thyrses 5–14 cm, ± interrupted; proximal bract margins serrate, sometimes entire; stems 10–27 cm. Penstemon cardwellii
8 Thyrses 1–6 cm, continuous; proximal bract margins entire; stems 4–10(–17) cm. Penstemon davidsonii
7 Corollas pink, red, rose red, scarlet, pinkish lavender, lavender, or purple; leaves usually glaucous; stamens: longer pair exserted (included in P. newberryi var. berryi). > 9
9 Verticillasters 4–12; corollas moderately to densely white-lanate internally abaxially. Penstemon newberryi
9 Verticillasters 1–3; corollas glabrous internally or sparsely white-lanate abaxially. Penstemon rupicola