Penstemon deustus

Douglas ex Lindley

Edwards’s Bot. Reg. 16: plate 1318. 1830. (as Pentstemon deustum)

Common names: Hot-rock beardtongue
Treatment appears in FNA Volume 17. Treatment on page 200. Mentioned on page 183, 186, 201, 223.

Subshrubs. Stems ascending to erect, (6–)15–50 cm, retrorsely hairy, sometime glabrate, not glaucous. Leaves cauline, opposite, subopposite, or whorled, not leathery, glabrous or retrorsely hairy; cauline 5–9 pairs, petiolate or sessile, (7–)10–50(–52) × (0.5–)1–20 mm, blade oblanceolate to ovate or spatulate, lanceolate to linear distally, base of proximals tapered, distals clasping, margins serrate to serrulate, rarely entire, apex rounded to obtuse, acute, or acuminate. Thyrses interrupted, cylindric, 6–30 cm, axis ± glandular-pubescent, verticillasters 5–11, cymes 1–6-flowered, 2 per node; proximal bracts lanceolate to linear, 6–40 × 1–4 mm, margins entire or serrate to serrulate; peduncles and pedicels ascending to erect, glandular-pubescent. Flowers: calyx lobes ovate to lanceolate, 2.3–7 × 0.6–1.9 mm, glandular-pubescent; corolla white to ochroleucous, sometimes tinged lavender, with brownish or purple nectar guides, funnelform, 9–18 mm, glabrate to glandular-pubescent externally, glandular-pubescent internally, sometimes glabrous or glabrate adaxially, tube 4–5 mm, throat slightly inflated, 2.5–5 mm diam., slightly 2-ridged abaxially; stamens: longer pair slightly exserted, pollen sacs opposite, explanate, 0.4–0.8 mm, dehiscing completely, connective splitting, sides glabrous, sutures papillate; staminode 8–9 mm, exserted, 0.2–0.3 mm diam., tip straight, glabrous or distal 0.5–2.5 mm sparsely pilose or villous, hairs yellow or white, to 0.5 mm; style 7–10 mm. Capsules 3–5 × 2.5–4 mm, glabrous.


Calif., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.


Varieties 4 (4 in the flora).

Penstemon deustus comprises four marginally discrete varieties. Extreme forms of each variety are distinctive, but extensive zones of contact exist among the varieties, and populations frequently exhibit degrees of intermediacy, especially in Oregon where all four varieties occur.

The Paiute and Shoshoni tribes, centered in the Great Basin, used Penstemon deustus to treat dermatological, gastrointestinal, immunological, and other disorders (D. E. Moerman 1998).

Selected References



1 Leaves whorled, sometimes opposite or subopposite, blades oblanceolate or lanceolate to linear, margins serrate to serrulate distally or entire. Penstemon deustus var. variabilis
1 Leaves opposite, blades ovate, spatulate, oblanceolate, or lanceolate, margins sharply to obscurely serrate, sometimes entire. > 2
2 Calyx lobes lanceolate, (3.5–)4–7 mm, apices acuminate; corollas 9–12 mm; cauline leaf blade margins sharply serrate. Penstemon deustus var. suffrutescens
2 Calyx lobes ovate to lanceolate, 2.3–5(–6.3) mm, apices acute to acuminate; corollas 10–18 mm; cauline leaf blade margins obscurely to sharply serrate, sometimes entire. > 3
3 Corollas 12–18 mm, glandular-pubescent externally, glandular-pubescent internally, sometimes obscurely adaxially, abaxial lobes white to ochroleucous, sometimes tinged lavender. Penstemon deustus var. deustus
3 Corollas 10–12(–15) mm, glabrate or glandular-pubescent externally, glabrous internally, or glabrate or glandular-pubescent abaxially and glabrous adaxially, abaxial lobes brown, sometimes white to ochroleucous. Penstemon deustus var. pedicillatus