Penstemon debilis
Author: O'Kane & J. Anderson


Parachute penstemon


Scrophulariaceae (Figwort Family)

Close up of Penstemon debilis by Steve O'Kane
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Close up of Penstemon debilis by Alicia Langton
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Ranks and Status

Global rank: G1
State rank: S1
Federal protection status: USFWS Threatened
State protection status: None

[+] Description and Phenology

Penstemon debilis by Suzanne Wuerthele
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General description: Penstemon debilis is a member of the figwort family (Schrophulariaceae). It is an herbaceous perennial which often forms mats or trails where the stems may root at the node. The flowers are white to lavender. There are no basal leaves and the cauline leaves are sessile, opposite, succulent and blue-glaucous (O'Kane and Anderson 1987).

Look Alikes: Easily distinguished from other Penstemon species by its weak stems, succulent, glabrous, and glacous leaves, and its white to pale lavender corollas (Spackman et al. 1997). 

Phenology: Flowers from mid June to mid July.  Fruits mid July-August (Colorado Natural Heritage Program 2012).

[+] Habitat

Habitat of Penstemon debilis courtesy of the Colorado Natural Heritage Program
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Habitat of Penstemon debilis by Susan Spackman Panjabi
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Sparsely vegetated, south-facing, steep, white shale talus of the Parachute Creek Member of the Green River Formation. Soils are a mixture of thin shale fragments and clay (Spackman et al. 1997).  Associated species include: Agropyron spicatum, Cercocarpus montanus, Chrysothamnus viscidiflorus, Cymopterus hendersonii, Eriogonum lonchophyllum, Galium coloradoense, Holodiscus dumosus, Machaeranthera grindeliodes, Monardella odoratissima, Astragalus lutosus, Festuca dasyclada, and Thalictrum heliophilum (O'Kane and Anderson 1987).

Sparsely vegetated, south-facing, steep, white shale talus of the Parachute Creek Member of the Green River Formation. Soils are a mixture of thin shale fragments and clay (Spackman et al. 1997). Associated species include: Agropyron spicatum, Cercocarpus montanus, Chrysothamnus viscidiflorus, Cymopterus hendersonii, Eriogonum lonchophyllum, Galium coloradoense, Holodiscus dumosus, Machaeranthera grindeliodes, Monardella odoratissima, Astragalus lutosus, Festuca dasyclada, and Thalictrum heliophilum (O'Kane and Anderson 1987).

Elevation Range: 5,597 - 9,167 feet (1,706 - 2,794 meters)

[+] Distribution

Distribution of Penstemon debilis in Colorado.
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Colorado endemic: Yes
Global range: Penstemon debilis is endemic to Garfield County, Colorado. This species is restricted to the Piceance Basin and a specific geologic substrate, the Mahogany Zone of the Parachute Creek Member of the Green River Formation. Despite extensive research in the Piceance Basin of Colorado (Peterson and Baker 1982, Harner and Associates 1984, Union Oil Company of California 1984, Spackman et al. 1997, and Rondeau et al. 1996), P. debilis is still known only from this small area in Garfield County. Estimated range is 35 square kilometers, calculated in 2008 by the Colorado Natural Heritage Program in GIS by drawing a minimum convex polygon around the known occurrences.

[+] Threats and Management Issues

Summary results of an analysis of the status of Penstemon debilis based on several ranking factors. This species was concluded to be "under conserved”. From Rondeau et al. 2011.
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Oil and gas development is considered to be the primary threat to the species (Rondeau et al. 2011). Natural gas production in particular, is a significant threat to this species, with increased energy development under way in the region in which these plants occur. The largest documented occurrence is on private land within a State Natural Area. The owner is working with the Colorado Natural Areas Program on best management practices to protect the species from oil and gas development activity. Other possible threats include grazing, recreation, and habitat fragmentation from roads. Road and communication tower maintenance could also cause habitat degradation (USFWS 2005).  Oil shale development is also a serious threat for this oil shale endemic and others, but is generally not economically justifiable at present. However, unconventional oil and gas exploration is a key feature of the Energy Policy Act of 2005. 'The Energy and Policy Act of 2005 establishes that oil shale, tar sands, and other strategic unconventional fuels should be developed to reduce the nation's dependency on on imported oil. Section 309(m)(1)(B) identifies the Green River Region ... (U. S. Fish and Wildlife Service 2005), as a priority for oil shale and tar sand development (USFWS 2006). Further, the Federal Register says, 'pressure to develop energy reserves in this area is intense' (USFWS 2006).

 

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Anderson, J. 1986. Plants collected during 1986 by J. Anderson deposited at the University of Colorado Herbarium, Boulder, Colorado.
    • Dawson, C. 2009. Personal communication with Colorado Natural Heritage Program staff regarding BLM rare plant monitoring in Colorado.
    • 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.
    • Irelend, T. 2002. Candidate and listing priority assignment form: Penstemon debilis. U.S. Fish and Wildlife Service, Grand Junction, Colorado.
    • 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.
    • Kraushaar, J.J., and R.A. Ristinen. 1988. Shale Oil. Pages 69-83 in Energy and Problems of a Technical Society. John Wiley and Sons, New York, New York.
    • McMullen, A.L. In preparation. The reproductive biology and edaphic endemism of the rare Colorado endemic PENSTEMON DEBILIS (Scrophulariaceae). Thesis. Utah State University, Logan, Utah.
    • Murray, D.K., and J.D. Haun. 1974. Introduction to the geology of the Peceance Creek Basin and vicinity, Northwestern Colorado. Pages 29-39 in D.K. Murray, editor. Energy resources of the Piceance Creek Basin, Colorado, Twenty-fifth field conference. Rocky Mountain Association of Geologists, Denver, Colorado.
    • 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. and J. H. Broderick. 2004. Petition to list Parachute Penstemon (Penstemon debilis) as threateed or endangered, prepare and emergency listing rule, and designate critical habitat under the Endangered Species Act (16 U. S. C. 1531, ET SEQ.) . Center for Native Ecosystems, Denver, CO and Colorado Native Plant Society. Ft. Collins, CO.
    • O'Kane, S.L., Jr., and J.L. Anderson. 1987. Penstemon debilis (Scrophulariaceae): a new species from Colorado endemic to oil shale. Brittonia 39: 412-416.
    • Rocky Mountain Society of Botanical Artists. 2009. RARE Imperiled Plants of Colorado, a traveling art exhibition. Exhibition catalogue developed by the Denver Botanic Gardens and Steamboat Art Museum.
    • 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.
    • Rondeau, R.J., M.B. Wunder, A. Meredith, C.A. Pague, and S. Spackman. 1996. Biological survey of Naval Oil Shale Reserve No. 1 (NOSR-1). Unpublished report for the Department of Energy, Casper, Wyoming by the Colorado Natural Heritage Program, Fort Collins, Colorado.
    • Scheck, C. 1994. Special Status Plants Handbook Glenwood Springs Resource Area. Unpublished report prepared for the Bureau of Land Management, Glenwood Springs, CO.
    • Spackman, S. 1996. Colorado Natural Heritage Program Field Survey for Penstemon debilis.
    • 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.
    • Spackman, S., K. Fayette, K. Carsey, and R. Rondeau. 1997. Field survey and protection recommendations for the globally imperiled parachute Penstemon, PENSTEMON DEBILIS. Unpublished report for the Colorado Natural Areas Program, Denver, Colorado by the Colorado Natural Heritage Program, Fort Collins, Colorado.
    • U.S. Fish and Wildlife Service (USFWS). 2004. Species assessment and listing priority assignment form. Penstemon debilis. 10 pp.
    • U.S. Fish and Wildlife Service (USFWS). 2005. Endangered and threatened wildlife and plants; reivew of native species that are canddates or proposed for listing as endangered or threatened; annual notice of findings on resubmitted petitions; annual description of progress on listing actions; proposed rule. Federal Register 70(90):24883.
    • U.S. Fish and Wildlife Service. 1996. Endangered and threatened wildlife and plants; review of plant and animal taxa that are candidates for listing as endangered or threatened species. Federal Register 61(40):7596-7613.
    • USDA, NRCS. 2013. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
    • 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.

Last Updated

2014-11-20