Penstemon leiophyllus

Pennell

Contr. U.S. Natl. Herb. 20: 346. 1920.

Common names: Charleston beardtongue
Endemic
Treatment appears in FNA Volume 17. Treatment on page 170. Mentioned on page 156, 171.

Stems ascending to erect, 4–55(–80) cm, glabrous, not glaucous. Leaves basal and cauline, not leathery, glabrous, not glaucous; basal and proximal cauline (20–)30–100 × 4–15(–20) mm, blade oblanceolate, base tapered, margins entire, apex obtuse to acute; cauline 2–7 pairs, sessile or proximals sometimes short-petiolate, 16–80 × 2–20 mm, blade lanceolate to linear, base tapered, apex obtuse to acute. Thyrses interrupted or continuous, secund, (1–)3–30(–40) cm, axis glandular-pubescent, verticillasters 2–8(–12), cymes 1–3(or 4)-flowered, (1 or)2 per node; proximal bracts lanceolate, (6–)10–60 × (1–)3–24 mm; peduncles and pedicels glandular-pubescent. Flowers: calyx lobes lanceolate, (3.8–)4.5–8.5 × 1.6–3.8 mm, glandular-pubescent; corolla violet to blue or purple, with violet or reddish purple nectar guides, ventricose, 18–35 mm, glandular-pubescent externally, glabrous or white-lanate internally abaxially, glandular-pubescent adaxially, tube 6–10 mm, throat gradually inflated, not constricted at orifice, 5–10 mm diam., 2-ridged abaxially; stamens: longer pair reaching orifice, pollen sacs divergent to nearly opposite, navicular, 1.2–2 mm, dehiscing incompletely, proximal 1/5 indehiscent, connective not splitting, sides glabrous, sutures denticulate, teeth to 0.1 mm; staminode 10–14 mm, included, 0.4–0.5 mm diam., tip straight, distal 1–5 mm sparsely to densely pilose, hairs yellow or orangish yellow, to 1 mm; style 12–19 mm. Capsules 7–11 × 5–6 mm.

Discussion

Varieties 3 (3 in the flora).

F. S. Crosswhite (1967) recognized three species in the Penstemon leiophyllus complex: P. francisci-pennellii, P. keckii, and P. leiophyllus. N. H. Holmgren (1984) expanded P. leiophyllus to include the other species as varieties. The complex is unique in the section in having patches of glandular hairs on the internal, adaxial surfaces of the corolla throats. The varieties are essentially allopatric; characters distinguishing them are minor.

Selected References

None.

Key

1 Stems 15–55(–80) cm; cauline leaves 4–20 mm wide, blades lanceolate, usually flat and straight; corollas glabrous, rarely white-lanate, internally abaxially; Utah. Penstemon leiophyllus var. leiophyllus
1 Stems 4–25(–43) cm; cauline leaves 2–5(–10) mm wide, blades lanceolate to linear, usually folded lengthwise and curved; corollas white-lanate, rarely glabrous, internally abaxially; Nevada. > 2
2 Corollas (22–)25–35 mm; Lincoln, Nye, and White Pine counties, Nevada. Penstemon leiophyllus var. francisci-pennellii
2 Corollas 18–22 mm; Clark County, Nevada. Penstemon leiophyllus var. keckii