Penstemon guadalupensis

Stems ascending to erect, 20–50 cm, retrorsely hairy. Leaves basal and cauline, not leathery, glabrous or glabrate, rarely basal retrorsely hairy along midvein; basal and proximal cauline petiolate, 25–95 × 1–6 mm, blade linear, rarely lanceolate, base tapered, margins entire, apex acute; cauline 6–11, sessile or proximals short-petiolate, 22–65 (–95) × 1–10 (–18) mm, blade lanceolate to linear, base tapered to clasping, margins entire or obscurely serrate, apex acute. Thyrses continuous or ± interrupted, cylindric, 3–16 (–26) cm, axis glandular-pubescent, verticillasters 3–8, cymes 2–4-flowered, 2 per node; proximal bracts lanceolate, 15–48 × 3–8 mm; peduncles and pedicels glandular-pubescent. Flowers: calyx lobes lanceolate, 5–6.5 × 1.2–2 mm, glandular-pubescent; corolla white, sometimes tinged pink or lavender, with reddish violet nectar guides, funnelform, 13–20 mm, glandular-pubescent and sparsely white-villous internally abaxially, tube 4–6 mm, throat gradually inflated, not constricted at orifice, 6–7 mm diam., rounded abaxially; stamens included, pollen-sacs opposite, explanate, 0.8–1 mm, dehiscing completely, sutures smooth; staminode 10–14 mm, reaching orifice or exserted, 0.5–0.7 mm diam., tip straight to recurved, distal 3–7 mm sparsely pilose, hairs yellow, to 0.9 mm; style 9–12 mm. Capsules 7–9 × 4.5–6 mm.

Phenology: Flowering Mar–Jun.
Habitat: Sandy or gravelly, calcareous soils, prairies.
Elevation: 400–800 m.

Tex.

Discussion

Penstemon guadalupensis is known from the southern Cross Timbers and Prairies, Edwards Plateau, and southern Rolling Plains physiographic provinces of central Texas. Pennell distinguished subsp. ernestii by its shorter corollas and broader leaves, but that distinction seems trivial.

Selected References

None.

Lower Taxa