Penstemon albomarginatus
Contr. W. Bot. 12: 61. 1908.
Herbs. Stems ascending, 10–35 cm, glabrous, glaucescent, proximal stems usually buried, rhizomelike. Leaves cauline, leathery, glabrous; cauline 2–5 pairs, short-petiolate or sessile, 18–60 × 5–22 mm, blade spatulate to obovate, base tapered, margins entire, apex rounded to obtuse or truncate. Thyrses continuous or interrupted, cylindric, 5–12 cm, axis glabrous, verticillasters 3–7, cymes (1–)3–8-flowered, 2 per node; proximal bracts oval to oblong, 22–44 × 8–18 mm, margins entire or erose; peduncles and pedicels ascending to erect, glabrous. Flowers: calyx lobes ovate-oblong to lanceolate, 3–5 × 1.4–2.1 mm, glandular-pubescent; corolla pinkish lavender, with reddish or violet nectar guides, funnelform, 13–18 mm, glabrous externally, moderately yellowish pilose internally abaxially, tube 4–6 mm, throat gradually inflated, 4–6 mm diam., 2-ridged abaxially; stamens included, pollen sacs opposite, explanate, 0.8–1.1 mm, dehiscing completely, connective splitting, sides glabrous, sutures smooth; staminode 5–7 mm, reaching orifice, 0.2–0.3 mm diam., tip straight to slightly recurved, glabrous; style 7–10 mm. Capsules 8–11 × 5–7 mm, glabrous. 2n = 16.
Phenology: Flowering Apr–Jun.
Habitat: Aeolian and colluvial sand, desert sand dunes and scrub.
Elevation: 500–1800 m.
Distribution
Ariz., Calif., Nev.
Discussion
Penstemon albomarginatus is known from northwestern Arizona (Mohave County), southeastern California (San Bernardino County), and southern Nevada (Clark and Nye counties). The species is morphologically anomalous in sect. Penstemon and probably belongs elsewhere in subg. Penstemon.
Selected References
None.