Penstemon tenuis

Herbs. Stems ascending to erect, 25–85 cm, glabrate or puberulent, not glaucous. Leaves basal and cauline, basal often withering by anthesis, not leathery, glabrous or ± puberulent along major veins; basal and proximal cauline 65–160 × 8–48 mm, blade oblanceolate to elliptic, base tapered, margins serrate, sometime subentire, apex obtuse to acute; cauline (3–)7 or 8 pairs, sessile, 45–140 × 6–37 mm, blade lanceolate, proximals sometimes oblanceolate, base truncate to clasping, margins sharply serrate, sometimes ± serrate, apex acute to acuminate. Thyrses interrupted, conic, 6–20 cm, axis glabrous or retrorsely hairy, rarely ± glandular-pubescent distally, verticillasters 3–8, cymes (3–)5–15-flowered, 2 per node; proximal bracts lanceolate, 22–100 × 6–30 mm, margins serrate; peduncles and pedicels ascending, retrorsely hairy or ± glandular-pubescent distally. Flowers: calyx lobes ovate to lanceolate, 3.1–6 × 1–2.2 mm, glabrous or sparsely glandular-pubescent; corolla lavender to violet, with sometimes faint reddish purple nectar guides, funnelform, 10–14 mm, sparsely glandular-pubescent externally, moderately to densely white-villous internally abaxially, tube 4–6 mm, throat moderately inflated, 4–6 mm diam., rounded abaxially; stamens included, pollen sacs opposite, navicular, 0.8–1 mm, dehiscing completely, connective splitting, sides glabrous, sutures smooth or ± papillate; staminode 8–9 mm, exserted, 0.3–0.4 mm diam., tip straight, distal 4–5 mm moderately to densely pubescent, hairs orangish, to 1 mm; style 8–10 mm. Capsules 4–5 × 3–4 mm, glabrous.

Phenology: Flowering Apr–Jun.
Habitat: Alluvial soils, open floodplain forests, open hardwood flatwoods, marsh margins, low prairies, wet depressions.
Elevation: 0–200 m.

Ark., La., Miss., Mo., Tex.

Discussion

Penstemon tenuis is widespread in the western Gulf Coastal Plain and lower Mississippi River Basin.

Selected References

None.

Lower Taxa