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Montana Field Guide

Montana Field Guides

Whipple's Beardtongue - Penstemon whippleanus

Species of Concern
Native Species

Global Rank: G5
State Rank: S2
(see State Rank Reason below)
State Threat Score: No Known Threats

Agency Status


External Links

State Rank Reason (see State Rank above)
Whipple's beardtongue occurs at the edge of its range in Montana, and is known here from just two collections, only one of which is recent. The species occupies high elevation, rocky habitat that is relatively unthreatened.
  • Details on Status Ranking and Review
    Whipple's Beardtongue (Penstemon whippleanus) Conservation Status Review
    Review Date = 05/29/2013
    View State Conservation Rank Criteria
    Population Size

    Score2-3 - Very Small to Small: Population size is imprecisely known but is believed to be <10,000 individuals.

    CommentPopulation size is poorly documented.

    Range Extent

    Score2 - Regional or State Endemic or Small Montana Range: Generally restricted to an area <100,000 sq. miles (equivalent to 2/3 the size of Montana or less) or Montana contributes 50% or more of the species’ range or populations OR limited to 2-3 Sub-basins in Montana.

    Area of Occupancy

    Score3 - Very Low: Generally occurring in 3 or fewer Subwatersheds (6th Code HUC’s).

    Environmental Specificity

    Score1 - Moderate: Species is restricted to a specific habitat that is more widely distributed or to several restricted habitats and is typically dependent upon relatively unaltered, good-quality habitat (C Values of 5-7).

    CommentOccurs in a variety of open, subalpine habitats.


    ScoreNA - Rank factor not assessed.


    ScoreNA - Rank factor not assessed.

    CommentPotential threats have not been analyzed, though habitat is relatively remote.

    Intrinsic Vulnerability

    Score1 - Moderate Vulnerability: Specific biological attributes, unusual life history characteristics or limited reproductive potential makes the species susceptible to extirpation from stochastic events or other adverse impacts to its habitat and slow to recover.

    Raw Conservation Status Score

    Score 9 to 10 total points scored out of a possible 13 (Rarity factors only).

General Description
Whipple's Beardtongue is a perennial herb with tufted stems that are 2-6 dm tall and arising from a shallow, branched rootcrown. The basal leaves each have an entire-margined, elliptic blade that is up to 6 cm long and a petiole of nearly the same length. The opposite stem leaves are narrower and mostly lack petioles. Foliage is glabrous below but glandular-hairy above. The inflorescence consists of 2-7 clusters of short-stalked flowers in the axils of reduced upper leaves. The tubular corolla is flared and 2-lipped at the mouth, 18-28 mm long, and blue to lavendar or cream-colored with glandular hairs on the outside. The 5 narrowly lance-shaped calyx segments are 7-11 mm long and are green throughout and glandular-hairy. The 4 anthers are glabrous, and the sterile stamen is bearded only at the tip. The fruit is a capsule that is 6-9 mm long and sparsely glandular-hairy near the top.

Flowering occurs in late July-early August.

Diagnostic Characteristics
Differing from other species of Penstemon in Montana by its large (>18 mm long), expanded (rather than narrowly tubular) flowers and a glandular inflorescence. Penstemon fruticosus, P. ellipticus, P. lyallii and P. montanus are woody at the base and have woolly anthers. Penstemon eriantherus has similar flowers but the basal leaves are narrower and have toothed margins.

Species Range
Montana Range Range Descriptions


Range Comments
Eastern ID and southwestern MT, south to UT, CO, AZ, and NM. Peripheral.

Observations in Montana Natural Heritage Program Database
Number of Observations: 5

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

This species inhabits open, rocky slopes in meadows and scattered timber of the subalpine and alpine zones. The only recently documented population in Montana was found in an open meadow and adjoining forest along an avalanche chute and lower scree slopes near the headwaters of a small stream. Soils are moist, alluvial and colluvial silt loam on a gentle (5%) northwestern slope (Culver 1993). Associates include Artemisia ludoviciana (western mugwort), Bromus ciliatus (fringed brome), Carex vallicola (valley sedge), Epilobium latifolium (willow-herb), Fragaria virginiana (wild strawberry), Geum macrophyllum (large-leaved avens), Heracleum sphondylium (cow parsnip), Melica bulbosa (oniongrass), Poa glaucifolia (white poa), Trisetum spicatum (spike trisetum), and Valeriana dioica (northern valerian).
Predicted Suitable Habitat Model

This species has a Predicted Suitable Habitat Model available.

To learn how these Models were created see

The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus vagans, Bombus appositus, Bombus auricomus, Bombus bifarius, Bombus centralis, Bombus fervidus, Bombus flavifrons, Bombus frigidus, Bombus huntii, Bombus melanopygus, Bombus mixtus, Bombus nevadensis, Bombus rufocinctus, Bombus sylvicola, Bombus occidentalis, Bombus pensylvanicus, Bombus bimaculatus, Bombus griseocollis, Bombus impatiens, Bombus insularis, Bombus suckleyi, Bombus bohemicus, and Bombus kirbiellus (Macior 1974, Thorp et al. 1983, Bauer 1983, Mayer et al. 2000, Wilson et al. 2010, Colla and Dumesh 2010, Colla et al. 2011, Koch et al. 2012, Pyke et al. 2012, Miller-Struttmann and Galen 2014, Williams et al. 2014, Tripoldi and Szalanski 2015).

The Beaverhead County population is in a BLM Wilderness Study Area that has little grazing and no discernable threats.

Threats or Limiting Factors
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).

  • Literature Cited AboveLegend:   View Online Publication
    • Bauer, P.J. 1983. Bumblebee pollination relationships on the Beartooth Plateau tundra of Southern Montana. American Journal of Botany. 70(1): 134-144.
    • Colla, S., L. Richardson, and P. Williams. 2011. Bumble bees of the eastern United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 103 p.
    • Colla, S.R. and S. Dumesh. 2010. The bumble bees of southern Ontario: notes on natural history and distribution. Journal of the Entomological Society of Ontario 141:39-68.
    • Koch, J., J. Strange, and P. Williams. 2012. Bumble bees of the western United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 143 p.
    • Macior, L.M. 1974. Pollination ecology of the Front Range of the Colorado Rocky Mountains. Melanderia 15: 1-59.
    • Mayer, D.F., E.R. Miliczky, B.F. Finnigan, and C.A. Johnson. 2000. The bee fauna (Hymenoptera: Apoidea) of southeastern Washington. Journal of the Entomological Society of British Columbia 97: 25-31.
    • Miller-Struttmann, N.E. and C. Galen. 2014. High-altitude multi-taskers: bumble bee food plant use broadens along an altitudinal productivity gradient. Oecologia 176:1033-1045.
    • Pyke, G.H., D.W. Inouye, and J.D. Thomson. 2012. Local geographic distributions of bumble bees near Crested Butte, Colorado: competition and community structure revisited. Environmental Entomology 41(6): 1332-1349.
    • Thorp, R.W., D.S. Horning, and L.L. Dunning. 1983. Bumble bees and cuckoo bumble bees of California (Hymenoptera: Apidae). Bulletin of the California Insect Survey 23:1-79.
    • Tripoldi, A.D. and A.L. Szalanski. 2015. The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 50: doi:
    • Williams, P., R. Thorp, L. Richardson, and S. Colla. 2014. Bumble Bees of North America. Princeton, NJ: Princeton University Press. 208 p.
    • Wilson, J.S., L.E. Wilson, L.D. Loftis, and T. Griswold. 2010. The montane bee fauna of north central Washington, USA, with floral associations. Western North American Naturalist 70(2): 198-207.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Culver, D.R. 1993. Sensitive plant species inventory in the Centennial Valley, Beaverhead County, Montana. Unpublished report to the Butte District, Bureau of Land Management. Montana Natural Heritage Program, Helena, 42 pp. plus appendices.
    • Culver, D.R. 1994. Floristic analysis of the Centennial Region, Montana. M.Sc. Thesis. Montana State University, Bozeman. 199 pp.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
    • Strickler, D. 1997. Northwest penstemons. Flower Press, Columbia Falls, Montana. 191 pages.
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Citation for data on this website:
Whipple's Beardtongue — Penstemon whippleanus.  Montana Field Guide.  .  Retrieved on , from