Scientific Name : Penstemon grahamii
Author : Keck
NatureServe Explorer
Common Name : Graham Beardtongue
Current Research Activities
1997 profile
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Taxonomy
Plantaginaceae (plantain family)
Ackerfield (2015, 2022) places this genus in the Plantaginaceae family.
Ranks and Status
State Rank : S1
State Rank Reason : Penstemon grahamii is known from a small area in Rio Blanco County, Colorado (USA). Only one of the seven occurrences is of good viability. The species is threatened primarily by oil and gas development and inappropriate livestock grazing, and is considered to be highly vulnerable to the effects of climate change.
U.S. Endangered Species Act : none
Colorado Threatened and Endangered List : none
Other Statuses : BLM, SWAP Tier 1
Description and Phenology
General Description:
Few-branched perennial herb to 2 dm in height from a tap-root. Leaves thick, entire, villous-glandular or glabrous, to 5 cm long and 18 mm wide. Basal leaves ovate spatulate or broadly oblanceolate, narrowed to a petiolar base. The opposite stem leaves lanceolate, sessile, and clasping. Flowers pinkish lavender with deep red guidelines in the throat. The inflorescence glandular-pubescent; the corolla 25 to 37 mm long; the golden yellow bearded staminode exserted.
Look Alikes:
Distinguished from other sympatric Penstemon species by the large, pinkish-lavender corollas with dark violet lines in the throat; and exserted, golden-yellow bearded staminode (Spackman et al. 1997).
Phenology:
Flowers from late May to early June (Spackman et al. 1997).
Habitat
Talus slopes and knolls of Green River Formation shales in sparsely vegetated desert shrub and pinyon-juniper communities (Spackman et al. 1997), Common associates include Juniperus osteosperma, Chamaechaenactis, Eriogonum ephedroides, Cercocarpus montanus, Forsellesia meionandra, and Parthenium ligulatum.
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Elevation Range:
5,506 - 6,822 feet (1,678 - 2,079 meters)
Distribution
Colorado Endemic:
No
Range:
Penstemon grahamii is known from Rio Blanco County in Colorado, USA. The estimated range extent in Colorado of 156 square kilometers was calculated in GeoCAT using occurrence data provided by the Colorado Natural Heritage Program (2023). This species can also be found in Carbon, Duchesne, and Uintah counties, Utah, USA.
Click on map to enlarge |
Threats and Management Issues
The primary threats to Penstemon grahamii arise from oil and gas development because this species occurs within an area of developed and expanding oil and gas fields with several wells and access roads in the immediate area (CNHP 2023, Handwerk et al. 2015, Rondeau et al. 2011). This can lead to potential elimination of occurrences/subpopulations, habitat degradation and fragmentation. Other threats include off-road vehicle use, competition from invasive plant species, native ungulate activity, and livestock disturbance (Handwerk et al. 2015, Krening and Hornbeck 2023). Four of the occurrences report evidence of livestock use in occupied habitat (CNHP 2023). An increase in invasive plant species frequencies was noted at multiple sites in 2022 (Krening and Hornbeck 2023). It is likely that livestock and native ungulate movements are influenced by drought and seasonal climate fluctuations (Krening and Hornbeck 2023). Disturbance created by livestock and ungulate hooves can create opportunities for invasive annual plant species to become established in habitats where they weren?t present previously. This species is considered to have low adaptive capacity and is expected to be highly vulnerable to climate change under both RCP 4.5 and 8.5 scenarios, as assessed for the 2025 Colorado State Wildlife Action Plan (CNHP 2025).
Summary results of an analysis of the status of Penstemon grahamii based on several ranking factors. This species was concluded to be weakly conserved. From Rondeau et al. 2011. |
References
- Ackerfield, J. 2015. Flora of Colorado. BRIT Press, Botanical Research Institute of Texas, Fort Worth, TX. 818 pp.
- Ackerfield, Jennifer. 2022. Flora of Colorado. Second Edition. Bot. Misc. 60. BRIT Press, Fort Worth Botanic Garden/Botanical Research Institute of Texas, U.S.A. 861 pp.
- Albee, B.J., L.M. Shultz, and S. Goodrich. 1988. Atlas of the vascular plants of Utah. Utah Museum Natural History Occasional Publication 7, Salt Lake City, Utah. 670 pp.
- Center for Native Ecosystems. 2002. Petition to List Graham's Penstemon (Penstemon grahamii) as Threatened or Endangered under the Endangered Species Act. Office of Endangered Species, U.S. Fish and Wildlife Service, U.S. Department of the Interior.
- Colorado Native Plant Society. 1989. Rare plants of Colorado. Rocky Mountain Nature Association, Colorado Native Plant Society, Estes Park, Colorado. 73 pp.
- Colorado Natural Heritage Program (CNHP). 2023. Biodiversity Tracking and Conservation System (Biotics 5). Colorado Natural Heritage Program, Colorado State University, Fort Collins.
- Colorado Natural Heritage Program (CNHP). 2025. Climate Change Vulnerability Assessment of Colorado Tier 1 and Tier 2 Plant Species of Greatest Conservation Need (SCGN) for the 2025 Colorado State Wildlife Action Plan. Colorado Natural Heritage Program, Colorado State University, Fort Collins, CO.
- Cronquist, A., A. H. Holmgren, N. H. Holmgren, J. L. Reveal and P. K. Holmgren. 1977. Intermountain Flora Vascular Plants of the Intermountain West, USA: vol. 6. New York Botanical Garden, Bronx, NY.
- Elliott, B. A., S. Spackman Panjabi, B. Kurzel, B. Neely, R. Rondeau, M. Ewing. 2009. Recommended Best Management Practices for Plants of Concern. Practices developed to reduce the impacts of oil and gas development activities to plants of concern. Unpublished report prepared by the Rare Plant Conservation Initiative for the National Fish and Wildlife Foundation.
- Graham, E. H. 1937. Botanical studies in the Uinta Basin of Utah and Colorado. Annals of the Carnegie Museum 26. Pittsburg, PA.
- Handwerk, J., L. Grunau, and S. Panjabi. 2015. Colorado Wildlife Action Plan: 2015 Rare Plant Addendum. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado, USA.
- Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
- Krening, P. and J. H. Hornbeck. 2023. Graham’s Beardtongue (Penstemon grahamii) and White River Beardtongue (Penstemon scariosus var. albifluvis). 2022 Population Monitoring Report. Prepared for The Penstemon Conservation Team: State of Utah School and Institutional Trust Lands Administration; Uintah County, Utah; Utah Public Lands Policy Coordination Office; Utah Division of Wildlife Resources; Rio Blanco County, Colorado; Bureau of Land Management; U.S. Fish and Wildlife Service. March 31, 2023.
- Krening, P. and J. Hope Hornbeck. 2021. Graham’s Beardtongue (Penstemon grahamii) and White River Beardtongue (Penstemon scariosus var. albifluvis) 2021 Population Monitoring Report. Prepared for The Penstemon Conservation Team: State of Utah School and Institutional Trust Lands Administration; Uintah County, Utah; Utah Public Lands Policy Coordination Office; Utah Division of Wildlife Resources; Rio Blanco County, Colorado; Bureau of Land Management; U.S. Fish and Wildlife Service. March 31, 2021.
- Neely, B., S. Panjabi, E. Lane, P. Lewis, C. Dawson, A. Kratz, B. Kurzel, T. Hogan, J. Handwerk, S. Krishnan, J. Neale, and N. Ripley. 2009. Colorado Rare Plant Conservation Strategy, Developed by the Colorado Rare Plant conservation Initiative. The Nature Conservancy, Boulder, Colorado, 117 pp.
- O'Kane, S. L. 1988. Colorado's Rare Flora. Great Basin Naturalist. 48(4):434-484.
- Rondeau, R., K. Decker, J. Handwerk, J. Siemers, L. Grunau, and C. Pague. 2011. The state of Colorado's biodiversity 2011. Prepared for The Nature Conservancy. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado.
- Shultz, L.M., and K.M. Mutz. 1979. Threatened and endangered plants of the Willow Creek drainage. Vol. 1: text. Prepared for the Bureau of Land Management, Vernal District Office, Vernal, Utah. 57 pp. + appendix.
- Spackman, S., B. Jennings, J. Coles, C. Dawson, M. Minton, A. Kratz, and C. Spurrier. 1997. Colorado rare plant field guide. Prepared for Bureau of Land Management, U.S. Forest Service and U.S. Fish and Wildlife Service by Colorado Natural Heritage Program.
- U.S. Fish and Wildlife Service (USFWS). 2013. Threatened Species Status for Graham's Beardtongue (Penstemon grahamii) and White River Beardtongue (Penstemon scariosus var. albifluvis). Federal Register 78(151): 47590-47611.
- U.S. Fish and Wildlife Service (USFWS). 2014. Withdrawal of the Proposed Rules To List Graham's Beardtongue (Penstemon grahamii) and White River Beardtongue (Penstemon scariosus var. albifluvis) and Designate Critical Habitat. Federal Register 79(151): 46042-46087.
- U.S. Fish and Wildlife Service (USFWS). 2019. Threatened Species Status for Graham's Beardtongue (Penstemon grahamii) and White River Beardtongue (Penstemon scariosus var. albifluvis); Designation of Critical Habitat for Graham's Beardtongue and White River Beardtongue Federal Register 84(177): 48090-48094. Online. Available: https://www.govinfo.gov/content/pkg/FR-2019-09-12/pdf/2019-19768.pdf#page=1
- U.S. Fish and Wildlife Service (USFWS). 2022. Withdrawal of the Proposed Rules To List Graham's Beardtongue (Penstemon grahamii) and White River Beardtongue (Penstemon scariosus var. albifluvis) as Threatened Species and To Designate Critical Habitat. Proposed rule; withdrawal. Federal Register 87(9): 2107-2125.
- U.S. Fish and Wildlife Service. 2006. Endangered and Threatened Wildlife and Plants; Proposed Threatened Status for Penstemon grahamii (Graham's beardtongue) With Critical Habitat; Proposed Rule. Federal Register 71(12): 3158-3196.
- USDA, NRCS. 2022. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
- Utah Conservation Data Center. 2003. Biological Conservation Datasystem. State of Utah Division of Wildlife Resources, Salt Lake City, Utah.
- Weber, W. A. and R. C. Wittmann. 2012. Colorado Flora, Western Slope, A Field Guide to the Vascular Plants, Fourth Edition. Boulder, Colorado. 532 pp.
- Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins. (Eds). 2015. A Utah flora, fifth edition, revised 2015. Monte L. Bean Life Science Museum, Provo, Utah. 987 pp.
