Penstemon nudiflorus
Proc. Amer. Acad. Arts 20: 306. 1885.
Stems erect, (35–)55–100 cm, glabrous, glaucous. Leaves basal and cauline, or basal absent or reduced, leathery, glabrous, glaucous; basal and proximal cauline 25–110 × (4–)10–27 mm, blade ovate to elliptic or lanceolate, base tapered, margins entire, apex obtuse to acute; cauline 3–6 pairs, sessile, (5–)15–105 × (1–)2–30 mm, blade lanceolate, base tapered to clasping, apex acute to acuminate. Thyrses interrupted, cylindric, 8–55 cm, axis glabrous, verticillasters 5–13, cymes 1- or 2(or 3)-flowered, (1 or)2 per node; proximal bracts lanceolate to subulate, 4–8 × 1–3 mm; peduncles and pedicels spreading to ascending, glabrous. Flowers: calyx lobes ovate to lanceolate, 4–5.8 × 2.5–3.2 mm, glabrous; corolla violet to lavender, with reddish purple nectar guides, ventricose-ampliate, 20–33 mm, glabrous externally, sparsely white-lanate internally abaxially, tube 7–9 mm, throat gradually to abruptly inflated, not constricted at orifice, 9–11 mm diam., rounded abaxially; stamens: longer pair exserted, pollen sacs opposite, navicular, 1.7–2.3 mm, dehiscing completely, sides glabrous, sutures denticulate, teeth to 0.1 mm; staminode 16–20 mm, reaching orifice or exserted, 0.5–0.8 mm diam., tip straight, distal 2–4 mm sparsely lanate, hairs yellow, to 1.5 mm; style 17–22 mm. Capsules 8–10 × 3–4 mm.
Phenology: Flowering May–Jun.
Habitat: Rocky, basaltic soils in pinyon-juniper woodlands.
Elevation: 1500–2300 m.
Discussion
Penstemon nudiflorus occurs mostly along the Mogollon Rim in central Arizona in Coconino, Gila, Mohave, Navajo, and Yavapai counties.
Selected References
None.