General: Snapdragon family (Scrophulariaceae). Large beardtongue is a native perennial that grows up to four feet tall. The leaves are opposite, simple, ovate to oblong, thick and fleshy; bluish-green with a waxy blue sheen and clasping at the base. The large two inch, pale purple flowers are five lobed and short lived (Runkel & Roosa 1989). The fruits are woody, egg shaped capsules that contain numerous small, angular, brown seeds (Freeman & Schofield 1991).
Distribution: Large beardtongue ranges from Wyoming to Texas, east to Wisconsin, Illinois, Missouri and Oklahoma (Steyermark 1963). For current distribution, please consult the Plant profile page for this species on the PLANTS Web site.
large-flowered beardtongue, showy beardtongue, pink beardtongue, shell-leaf penstemon, shell-leaf beardtongue, wild foxglove, Canterbury bells
Range and Habitat in Illinois
Regularity: Regularly occurring
Global Range: North Dakota, Wyoming, to Texas, east to Wisconsin, Indiana.
Penstemon grandiflorus is commonly found in prairies, often in sandy or loamy soils. This plant prefers acid, neutral and alkaline soils and requires well-drained soils. It grows well when planted in open dry situations (Steyermark 1963), and can grow in semi-shade or no shade.
There are many species of PENSTEMON in our area; however, the combination of exceptionally large flowers and glabrous inflorescence and anthers distinguish this species from others. A hand lens may be required for identification.
Range and Habitat in Illinois
Comments: Sandy to loamy prairies, open grassy areas. In Missouri it grows on prairie bluffs and loess hills in open grassy places (Steyermark, 1963).
Propagation by Seed: Penstemon grandiflorus seeds are best sown in the fall or spring in a greenhouse (Heuser 1997). The seeds should germinate within one to four months (Ibid.). When the seedlings are large enough to handle, place them into individual pots and plant them out in their permanent positions in the late spring.
Flower-Visiting Insects of Large-Flowered Penstemon in Illinois
(Long-tongued bees suck nectar or collect pollen; short-tongued bees collect only pollen; flies feed on pollen; the skipper sucks nectar; all observations are from Reed, except those from Clinebell & Bernhardt and Crosswhite & Crosswhite as indicated below)
Apidae (Bombini): Bombus affinis sn, Bombus auricomus sn, Bombus fervida sn, Bombus griseocallis sn (CB), Bombus pensylvanica sn (CB); Anthophoridae (Anthophorini): Anthophora terminalis sn; Anthophoridae (Ceratinini): Ceratina sp. cp; Anthophoridae (Eucerini): Synhalonia dubitata sn cp olg, Synhalonia hamata sn; Anthophoridae (Xylocopini): Xylocopa virginica prf sn@prf np (CB); Megachilidae (Megachilini): Megachile brevis sn (CB); Megachilidae (Osmiini): Hoplitis pilosifrons cp (Re, CB), Osmia distincta cp olg (Re, CC), Osmia simillima cp
Halictidae (Halictinae): Agapostemon virescens cp, Augochlorella persimilis cp (CB), Augochlorella striata cp fq (Re, CB), Lasioglossum spp. cp fq (CB), Lasioglossum acuminatum cp, Lasioglossum coriaceus cp, Lasioglossum cressonii cp, Lasioglossum nymphaearum cp, Lasioglossum paraforbesii cp, Lasioglossum pictus cp, Lasioglossum pilosus cp, Lasioglossum pruinosus cp, Lasioglossum rohweri cp; Colletidae (Hylaeinae): Hylaeus affinis cp, Hylaeus mesillae cp
Syrphidae: Sphaerophoria sp. fp; Anthomyiidae: Hylemya sp. fp
Hesperiidae: Polites peckius sn
Foodplant / spot causer
subimmersed, concentric to scattered pycnidium of Phyllosticta coelomycetous anamorph of Phyllosticta penstemonis causes spots on live leaf of Penstemon grandiflorus
Remarks: season: 10
National NatureServe Conservation Status
Rounded National Status Rank: NNR - Unranked
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Please consult the Plants Web site and your State Department of Natural Resources for this plant’s current status, such as, state noxious status, and wetland indicator values.
Cultivars, improved and selected materials (and area of origin)
Somewhat available through native plant seed vendors in the Great Plains region. Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”
Stem tip cuttings should be taken from the tips of healthy, non-flowering, semi-mature or mature shoots, between early summer and fall (Heuser 1997). Shoots can be cut into a number of usable sections at almost any time during the growing period (Ibid.).
Relevance to Humans and Ecosystems
Ethnobotanic: Native Americans treated toothache by chewing the root pulp of plants in this genus and placing it in the cavity (Runkel & Roosa 1989). The Navajo applied a wet dressing of pounded leaves of large beardtongue to rattlesnake bites; they considered this an absolute antidote (Ibid.). A decoction of the leaves has been used in the treatment of chills and fevers (Moerman 1998).
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