Penstemon scariosus var. albifluvis
Author: (England) N. Holmgren

White River penstemon

Scrophulariaceae (Figwort Family)

Close up of Penstemon scariosus var. albifluvus by Dave Elin
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Close up of Penstemon scariosus var. albifluvus by Dave Elin
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Taxonomic Comments

Microsattelite studies indicate that Penstemon albifluvis should be considered as a distinct species, not a variety of P. scariosus (Anderson 2016).

Ranks and Status

Global rank: G4T1
State rank: S1
Federal protection status: BLM Sensitive
State protection status: None

[+] Description and Phenology

Please see 1997 profile, and artwork in RARE and Imperiled Plants of Colorado (Rocky Mountain Society of Botanical Artists 2009).

General description: Herbaceous perennial to 5 dm in height with multiple stems from a woody caudex. The leaves are linear to linear-lanceolate and are typically less than 7 mm wide. The pale-blue to lavender corolla is prominently bilabiate, the lower lip larger than the upper. Corolla lobes are thin membranous-margined; the stamens exserted; the anthers white-bearded.  Inflorescence a cyme of 2 to 5 flowers.

Look Alikes: Clearly a close relative to Penstemon scariosus. This variety differs from typical P. scariosus as the corolla and anther hairs tend to be shorter, and the basal leaf rosette is reduced; habitat also differs. Also closely related to Penstemon strictus and other members of the complex by a series of small morphological features: P. scariosus var. albifluvis has basal leaves that are lacking or poorly developed contrasting well-developed basal leaves of relatives; anther hairs are longer than widths in relatives; corolla lenth is 20-22 mm in P. scariosus var. albifluvis, 24-30 mm in relatives (Galatowitsch 1985).

Phenology: Flowers from mid May through June (Spackman et al. 1997), with seeds produced in late June (Colorado Natural Heritage Program 2012).

[+] Habitat

Habitat of Penstemon scariosus var. albifluvus by Dave Elin
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Habitat of Penstemon scariosus var. albifluvus by Rusty Roberts
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Found in mixed desert shrub and pinyon-juniper communities on sparsely vegetated white shale slopes. Occurs on fine-textured calcareous soils that are shallow, and usually mixed with fragmented shale. These soils are derived from oil shale barrens of the Parachute Creek Member, Green River Formation (Spackman et al. 1997).

Elevation Range: 5,699 - 6,696 feet (1,737 - 2,041 meters)

[+] Distribution

Distribution of Penstemon scariosus var. albifluvus in Colorado.
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Colorado endemic: No
Global range: Endemic to Raven Ridge near the White River in Rio Blanco County, Colorado, westward into Bonanza, southern Uintah County., Utah, to the vicinity of Evacuation Creek, a distance of about 20 miles.
State range: Known from Rio Blanco County in Colorado. Estimated range in Colorado is 50 square kilometers, calculated in GIS by drawing a minimum convex polygon around the known occurrences (calculated by the Colorado Natural Heritage Program in 2008).

[+] Threats and Management Issues

Summary results of an analysis of the status of Penstemon scariosus var. albifluvus based on several ranking factors. This species was concluded to be “under conserved”. From Rondeau et al. 2011.
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The primary threat at this time is considered to be oil and gas development (Rondeau et al. 2011). 99% of the species total population occurs on substrates designated as a priority for oil shale and tar sand development; 100% of the population lies in an area with hydrocarbon resources. The known Colorado populations are within the Raven Ridge BLM ACEC and on BLM with no special protection status. The plants occur within an area of developed and expanding oil and gas fields with several wells and access roads; additional potential threats include off-road vehicle use and grazing.

[+] References

    • Anderson, C.D., N.J. Ricks, K.M. Farley, P.J. Maughan, and M.R. Stevens. 2016. Identification and characterization of microsatellite markers in Penstemon scariosus (Plantaginaceae). Applications in Plant Sciences 4(3): 1-5.
    • Cronquist, A., A.H. Holmgren, N.H. Holmgren, J.L. Reveal, and P.K. Holmgren. 1984. Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. Vol. 4, Subclass Asteridae (except Asteraceae). New York Botanical Garden, Bronx. 573 pp.
    • 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.
    • England, J. L. 1982. A new species of penstemon (Scophulariacede) from the Unita Basin of Utah and Colorado. Great Basin Naturalist 42(3):367-368.
    • Franklin, M.A. "Ben". 1995. Field inventory of Penstemon scariosus var. albifluvis (R.L. England) N. Holmgren in the Book Cliffs Resource Area, Uinta Basin, Utah. Final report for 1994 Challenge Cost Share Project. UDNR Utah Natural Heritage Program and BLM Vernal District. Pp. 1-9 + appendices. Unpublished report on file Utah Natural Heritage Program, Salt Lake City, Utah.
    • Franklin, M.A. 1994. Survey report on Penstemon pinorum L. Shultz & J. Shultz (pinyon penstemon). 1993 Challenge Cost Share Project. Utah Natural Heritage Program and Cedar City District Bureau of Land Management. Unpublished report on file Utah Natural Heritage Program, Salt Lake City. 7 pp. + appendices.
    • Galatawitsch, S. 1985. Plant Species of Special Concern.
    • 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.
    • 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.
    • Neese, E., and F. Smith. 1982. Final Report: Threatened and endangered plant inventory for the Oil Shale RMP, Bookcliffs Resource Area, Utah Bureau of Land Management, Vernal District. Volume 1 - Text. Pp 1-88 + appendices.
    • 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.
    • 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.
    • Stevens M.R., and R.L. Johnson. 2016. Annual APS Summer Meeting Rewards: Taxonomic clarification of two Penstemon species of the Uinta Basin of Colorado and Utah. Bulletin of the American Penstemon Society 75:8-20.
    • U.S. Fish and Wildlife Service (USFWS). 2004. Species assessment and listing priority assignment form. Penstemon scariosus var. albifluvis. 10 pp.
    • U.S. Fish and Wildlife Service. 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. 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.
    • 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.
    • Welsh, S.L., N.D. Atwood, L.C. Higgins, and S. Goodrich, eds. 1987. A Utah Flora. Great Basin Naturalist Memoir 9, Brigham Young University, Provo, Utah. 894 pp.
    • Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins (eds.) 1993. A Utah flora. 2nd edition. Brigham Young Univ., Provo, Utah. 986 pp.

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