Proc. Biol. Soc. Wash. 17: 100. 1904. (as Pentstemon)
Stems ascending to erect, 30–140(–160) cm, glaucous. Leaves glabrous, glaucous; basal and proximal cauline 40–160 × 14–40 mm, blade spatulate to oblanceolate or elliptic, base tapered, margins entire, apex rounded to obtuse or acute; cauline 3–8 pairs, sessile, (17–)44–115 × (4–)23–45 mm, blade ovate to oblanceolate or lanceolate, base tapered to cordate-clasping to connate-perfoliate, margins entire, apex rounded or obtuse to acute. Thyrses interrupted, cylindric, (15–)30–60(–90) cm, axis glabrous, verticillasters 9–12(–20), cymes (1–)3–9-flowered; proximal bracts ovate to lanceolate, 11–55 × 4–30 mm; peduncles and pedicels ascending to erect, glabrous or pedicels sparsely glandular-pubescent. Flowers: calyx lobes ovate to lanceolate, 2.8–5 × 1.5–2.1 mm, margins entire or erose, sparsely glandular-pubescent proximally, sometimes glabrous; corolla orangish pink to red, without nectar guides, nearly radially symmetric, weakly bilabiate, tubular-funnelform, 17–22 mm, glandular-pubescent externally, glandular-pubescent internally abaxially, tube 5–7 mm, throat slightly inflated, 4–6 mm diam., rounded abaxially; stamens included, pollen sacs explanate, 1–1.5 mm, sutures smooth; staminode 8–11 mm, flattened distally, 0.6–1 mm diam., tip straight, distal 2–3 mm retrorsely hairy, hairs yellow or whitish, to 1.5 mm; style 10–11 mm. Capsules 10–13 × 5–8 mm. 2n = 16.
Phenology: Flowering (Mar–)Apr–Jun.
Habitat: Gravelly or rocky canyons, slopes, washes, desert grasslands, pinyon-juniper and oak woodlands.
Elevation: 900–1800 m.
Ariz., N.Mex., Mexico (Chihuahua, Sonora).
Penstemon superbus is known from Cochise, Gila, Graham, Greenlee, and Pima counties, Arizona, Grant and Hidalgo counties, New Mexico, and in adjacent Chihuahua and Sonora, Mexico. The species resembles P. parryi; it differs by broader leaves and corollas that are orangish pink to red, more nearly radially symmetric, and without white hairs abaxially in the throats. Penstemon superbus also resembles P. alamosensis, which is known from New Mexico and Texas to the east of P. superbus. The glabrous staminode of P. alamosensis distinguishes it from P. superbus.