Penstemon azureus

Subshrubs. Stems ascending to erect, 13–50(–70) cm, glabrous, glaucous. Leaves basal and cauline, basal sometimes few, opposite, glabrous, glaucous; basal and proximal cauline 15–60 × 2–10(–20) mm, blade obovate to oblanceolate or linear, base tapered, margins entire, apex obtuse to acute; cauline 3–20 pairs, sessile or proximals short-petiolate, 10–90 × 2–20 mm, blade elliptic to ovate, lanceolate, or linear, base tapered to clasping or cordate-clasping, margins entire, apex obtuse to acute. Thyrses interrupted or continuous, secund, (3–)6–31 cm, axis glabrous, verticillasters 3–10, cymes 1–3(or 4)-flowered, 2 per node; proximal bracts ovate to lanceolate, 4–50 × 1–32 mm; peduncles and pedicels ascending to erect, glabrous. Flowers: calyx lobes ovate to oblong or obovate, 2.5–6.5 × 1.4–3.2 mm, glabrous; corolla violet to blue or purple, with or without purple nectar guides, funnelform to ventricose, 18–35 mm, glabrous externally, glabrous internally, tube 7–9 mm, throat gradually inflated, 8–10 mm diam., slightly 2-ridged abaxially; stamens: longer pair reaching orifice or exserted, filaments glabrous, pollen sacs parallel, 1.8–3.5 mm, distal 1/3–1/2 indehiscent, sides hispidulous to pilose, hairs white, to 0.8 mm near filament attachment, sutures denticulate, teeth to 0.3 mm; staminode 12–19 mm, included, 0.4–0.6 mm diam., glabrous; style 16–22 mm. Capsules 7–11 × 14–6 mm.

Distribution

w United States.

Discussion

Varieties 2 (2 in the flora).

Penstemon azureus occurs from southwestern Oregon to central California.

Selected References

None.

Lower Taxa

Penstemon azureus var. angustissimus, Penstemon azureus var. azureus

Key

1	Calyx lobes obovate to oblong, 2.5–4.8 × 2–3.2 mm, apices cuspidate to mucronate; cauline leaves 10–65 × 4–20 mm, blades elliptic to ovate or lanceolate.	Penstemon azureus var. azureus
1	Calyx lobes ovate, 5–6.5 × 1.4–2.3 mm, apices acuminate to caudate; cauline leaves 40–90 × 2–6 mm, blades lanceolate to linear.	Penstemon azureus var. angustissimus