Large Beardtongue

Penstemon grandiflorus

Large Beardtongue (Penstemon grandiflorus), also called Shell-leaf Penstemon, is a native perennial and the showiest penstemon in the Black Hills, with big lavender-pink tubular flowers and round, waxy, blue-gray leaves that wrap the stem. It blooms from late May through June on sandy, gravelly and rocky prairie in the foothills and open pine country.

Free photos from other sources

Large Beardtongue: Large lavender-pink tubular flowers on a stem in grassland — Shell-leaf penstemon. NPS/Michael Wheeler, Public Domain. Get it at the source

Large Beardtongue: Flowering stems beside last year's dark seed capsules on dry stalks — Penstemon grandiflorus - Larry Jensen 01. Larry Jensen, CC BY 4.0, resized. Get it at the source

Large Beardtongue: Pale pink flowers in spaced whorls, with old brown capsules — Penstemon grandiflorus - Larry Jensen 02. Larry Jensen, CC BY 4.0, resized. Get it at the source

Large Beardtongue: Bumble bee entering a pale lavender flower above round leaves that clasp the stem — Shell leaf Penstemon. USFWS Mountain-Prairie (Photo Credit: Krista Lundgren/FWS), Public Domain. Get it at the source

Large Beardtongue: Rosette of thick, blue-gray, spoon-shaped leaves — Penstemon grandiflorus - Mathew Zappa 01. Mathew Zappa, CC BY 4.0, resized. Get it at the source

Large Beardtongue: Flower stalk with whorls of large tubular flowers, the color shifted toward blue — Large Beardtongue (Penstemon grandiflorus). Jim Pisarowicz (National Park Service), Public Domain. Get it at the source

Quick facts
Family	Plantaginaceae · Plantain
Status	Native perennial
Blooms	Late May through June, with a few into early July
Height	30–100 cm (12–40 in)
Where	Dry sandy, gravelly or rocky prairie, foothills, limestone rims and open pine edges
Also called	Shell-leaf Penstemon, Shell-leaf Beardtongue, Large-flowered Beardtongue, Large-flowered Penstemon, Prairie Penstemon, kimímila tȟawánaȟča (Lakota)
Synonym	Penstemon bradburyi, Penstemon grandiflorum
Traditional use	Sitting Bull College's 1998 Culturally Important Plants of the Lakota says a decoction of the leaves was taken for chills and fever, and a decoction of the root for chest pain.

Roots, seeds & germination

Root: A stout, deep taproot topped by a woody crown that sends up one to a few stems. Plants are short-lived, usually 2 to 5 years, and the population carries on by reseeding.

Seed: A hard, egg-shaped capsule 1.6–2.5 cm (⅝–1 in) long turns dark brown and splits at the top in mid to late summer, holding many small, angular, brown to black seeds 2.5–4 mm long. The empty capsules often stay on last year's dead stalks into the next flowering season.

Germination: The seed needs a short cold, moist period, about 30 days, and SDSU calls sowing outdoors in fall, or in early spring while the ground is still cold, the easiest method. First-year plants make only a rosette of leaves, so flowers come no sooner than the second year. It needs full sun and good drainage.

How do you identify Large Beardtongue?

The leaves are the best mark: thick, smooth and blue-gray with a waxy bloom, round to broadly egg-shaped, in 4–8 opposite pairs whose bases clasp the stem like a pair of shells. The lavender to pink-lavender flowers are 3.5–4.8 cm (1⅜–1⅞ in) long, the largest of any Black Hills penstemon, with a short tube that swells into a wide, open throat, hairless inside and out. They stand in 3–7 spaced whorls above pairs of round, leafy bracts. Narrowleaf Beardtongue shares the blue-gray leaves, but they are narrow and its flowers are only 1.3–2.2 cm (½–⅞ in) long. Smooth Beardtongue has deep blue to violet flowers crowded to one side of the stalk and green, lance-shaped leaves.

When does it bloom?

Late May through June, with a few into early July.

Where does it grow?

Dry, open, sunny ground with sandy, gravelly or rocky, well-drained soil: mixed-grass prairie in the foothills, red-soil valleys, limestone rims and ledges, grassy openings in ponderosa pine and bur oak woods, and road cuts. National Park Service lists record it at Wind Cave, Mount Rushmore and Devils Tower. About 100 herbarium specimens have been collected across the Hills since 1887, including Custer State Park and the Wyoming Black Hills.