Penstemon cardinalis

Stems ascending to erect, 32–100 cm, glabrous, slightly glaucous. Leaves glabrous, not glaucous; basal and proximal cauline 40–80(–150) × 14–40(–60) mm, blade spatulate to obovate, oblanceolate, or elliptic, base tapered, margins entire, apex rounded to obtuse; cauline 3–7 pairs, sessile, (11–)20–135 × 9–50 mm, blade spatulate to elliptic, ovate, or subcordate, base truncate to broadly cordate-clasping, apex rounded to acute or mucronate. Thyrses secund, (3–)6–44 cm, axis glabrous, verticillasters 3–15, cymes 2–4(–8)-flowered; proximal bracts suborbiculate, ovate, or lanceolate, (4–)16–60 × (2–)5–45 mm; peduncles and pedicels erect, glabrous. Flowers: calyx lobes ovate, 1.6–6 × 1.4–3 mm, margins entire or erose, glabrous; corolla red to crimson, with reddish violet nectar guides, bilaterally symmetric, weakly bilabiate, tubular, 22–30 mm, densely yellow-villous internally abaxially, tube 6–8 mm, throat 6–8 mm diam., constricted at orifice, rounded abaxially, abaxial lobes spreading to reflexed, adaxial lobes projecting to erect; stamens included, pollen sacs divergent, 1.5–1.9 mm, sides glabrous, sutures denticulate, teeth to 0.1 mm; staminode 15–17 mm, included or slightly exserted, tip straight to recurved, distal 1–3 mm sparsely lanate, hairs yellow, to 1.5 mm; style 18–28 mm, usually exserted. Capsules 10–15 × 5–9 mm.

Distribution

sc United States.

Discussion

Varieties 2 (2 in the flora).

Penstemon cardinalis occurs as two weakly differentiated varieties in isolated ranges of the Southern Rocky Mountains.

Selected References

None.

Lower Taxa

Penstemon cardinalis var. cardinalis, Penstemon cardinalis var. regalis

Key

1	Calyx lobes 1.6–3.5(–4) × 1.4–2 mm; cauline leaf blades elliptic to spatulate or ovate, not leathery; proximal bracts ovate to lanceolate.	Penstemon cardinalis var. cardinalis
1	Calyx lobes 4–6 × 2.3–3 mm; cauline leaf blades ovate to subcordate, sometimes elliptic, leathery; proximal bracts suborbiculate to ovate.	Penstemon cardinalis var. regalis