Contr. U.S. Natl. Herb. 4: 170. 1893. (as Pentstemon)
Shrubs or subshrubs. Stems ascending to erect, 30–60 cm, glaucous. Leaves: cauline 6–12 pairs, sessile or short-petiolate, (12–)25–65 × 2–8 mm, blade lanceolate to linear, sometimes oblanceolate, base truncate or tapered, margins entire, rarely ± serrulate distally, apex obtuse to acute. Thyrses interrupted, cylindric, 8–30 cm, axis glabrous, verticillasters 3–8, cymes 1–3-flowered; proximal bracts lanceolate to linear, 9–28 × 2–5 mm; peduncles and pedicels spreading to ascending, glabrous. Flowers: calyx lobes depressed-ovate to round or ovate, 3.5–6.5 × 2.5–5 mm, glabrous; corolla bluish lavender to lavender or light pink, with reddish purple nectar guides, strongly bilabiate, ventricose-ampliate, 22–28 mm, glabrous or glandular-pubescent externally, moderately to densely white-lanate internally abaxially, sometimes also sparsely to densely glandular-pubescent internally, tube 6–8 mm, length 1–1.5 times calyx lobes, throat abruptly inflated, constricted at orifice, 8–14 mm diam., 2-ridged abaxially; stamens included, filaments of shorter pair glandular-puberulent proximally, pollen sacs explanate to subexplanate, 1.6–2.2 mm, sutures smooth; staminode 15–19 mm, exserted, 0.6–0.8 mm diam., tip recurved, distal 8–9 mm moderately pilose to lanate, hairs yellow, to 2.5 mm; proximal 5–6 mm glandular-pubescent; style 19–24 mm, glabrous. Capsules 9–13 × 5–7 mm, glabrous. 2n = 16.
Varieties 2 (2 in the flora).
Penstemon fruticiformis is known from the Mojave Desert. Specimens from the Kingston Range and the eastern flank of the southern Sierra Nevada sometimes combine features of P. fruticiformis and P. incertus.