Proc. Amer. Acad. Arts 15: 50. 1879. (as Pentstemon rattani)
Herbs. Stems ascending to erect, (15–)30–120 cm, glabrous, sometimes glabrous proximally, glandular-pubescent distally, not glaucous. Leaves basal and cauline, not leathery, glabrous; basal and proximal cauline 30–250 × 7–50 mm, blade elliptic to lanceolate, base tapered, margins serrate to dentate, apex obtuse to acute; cauline 2–5 pairs, short-petiolate or sessile, (10–)20–75(–110) × 5–30(–38) mm, blade oblong to triangular-ovate, base truncate to cordate-clasping distally, margins serrate to dentate, apex obtuse to acute. Thyrses interrupted, cylindric, 2–24 cm, axis glandular-pubescent, verticillasters 2–7, cymes 3–11-flowered, 2 per node; proximal bracts triangular to lanceolate, 6–50 × 1–22 mm, margins entire or ± serrate; peduncles and pedicels ascending to erect, glandular-pubescent. Flowers: calyx lobes ovate to ovate-oblong or lanceolate, 4–10 × (1–)1.5–2.5 mm, glandular-pubescent; corolla lavender to purple or violet, with reddish purple nectar guides, ventricose to ventricose-ampliate, 20–30 mm, glandular-pubescent externally, sparsely to densely white-lanate internally, tube 6–7 mm, throat abruptly inflated, 8–10 mm diam., 2-ridged abaxially; stamens included, pollen sacs opposite, subexplanate, 1.2–1.5 mm, dehiscing completely, connective splitting, sides glabrous, sutures smooth or papillate; staminode 21–26 mm, exserted, 0.3–0.4 mm diam., tip straight to recurved, distal 6–10 mm sparsely to moderately lanate, hairs white or yellow, to 3 mm; style 16–19 mm. Capsules 5–9 × 3.5–5 mm, glabrous. 2n = 16.
Varieties 2 (2 in the flora).
Penstemon rattanii comprises two morphologically distinct and geographically allopatric varieties confined to the Coast Range of California and Oregon.
|1||Calyx lobes usually longer than capsules, lanceolate, sometimes ovate, (5.5–)6.5–10 mm, apices acute to acuminate, sometimes obtuse; nw California, sw Oregon.||Penstemon rattanii var. rattanii|
|1||Calyx lobes usually shorter than capsules, ovate-oblong, 4–7 mm, apices obtuse to acute; wc California.||Penstemon rattanii var. kleei|