Penstemon fremontii var. glabrescens
Author: Dorn & Lichvar

Fremont's beardtongue

Scrophulariaceae (Figwort Family)

Close up of Penstemon fremontii var. glabrescens by Bernadette Kuhn
Click image to enlarge.

Taxonomic Comments

Johnson et al. 2016 published molecular and morphological evidence for Penstemon luculentus (Plantaginaceae) as a replacement name for P. fremontii var. glabrescens.  Weber and Wittmann (2012) feel that this variety is not closely related to P. fremontii and state that it might be better placed, as a species, closer to P. scariosus and P. gibbensii. This variety is not listed in Ackerfield 2012. Although Weber and Wittmann place the genus Penstemon in the Scrophulariaceae (Figwort Family), the Flora of North America (1993+) and Ackerfield (2012) place the genus in the Plantaginaceae (Plantain Family).

Ranks and Status

Global rank: G3G4T2
State rank: S2
Federal protection status: None
State protection status: None

[+] Description and Phenology

Penstemon fremontii var. glabrescens: artwork not available

General description:

Look Alikes: This taxon could be confused with P. fremontii  and P. scariosus var. garrettii, however, there are distinctions that can reliably segregate these taxa. Distinguishing characteristics are more apparent when comparing these taxa in situ.  Pubescence of the leaves appears to be the most reliable character. Penstemon fremontii var. glabrescens leaves are glabrous or glabrescent, except sometimes the margins and midveins, and the basal and proximal leaves are 2-12 mm wide. Var. fremontii leaves are densely puberulent or, rarely, glabrescent (pers. comm. Craig Freeman 2010). Peggy Lyon (pers. comm. 2012) notes that var. fremontii grows on deeper soils in more mesic sites; and it is taller than var. glabrescens.

Phenology: Flowers in June (Colorado Natural Heritage Program 2012).

[+] Habitat

Habitat of Penstemon fremontii var. glabrescens by Bernadette Kuhn
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Found on partly barren, arid benches and slopes in sandy clay loams of the Uinta Formation (and/or Green River shale?) in sagebrush communities with Amelanchier, Chrysothamnus, and Holodiscus (Colorado Natural Heritage Program).

Elevation Range: 5,515 - 8,583 feet (1,681 - 2,616 meters)

[+] Distribution

Distribution of Penstemon fremontii var. glabrescens in Colorado according to mapped land ownership/management boundaries (CNHP 2012, COMaP v9 ).
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Distribution of Penstemon fremontii var. glabrescens in Colorado
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Colorado endemic: Yes
Global range: Endemic to Colorado. Known only from Rio Blanco County. Estimated range is 992 square kilometers (383 square miles), 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 fremontii var. glabrescens based on several ranking factors. This species was concluded to be “Weakly Conserved”. From Rondeau et al. 2011.
Click image to enlarge.

This species occurs within the Piceance Basin, an area of active gas and oil drilling. Some sites may also be threatened by off road vehicle use and inappropriate grazing.

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Colorado Natural Heritage Program. 1997. Biological Conservation Datasystem.
    • Colorado Natural Heritage Program. 2009. The Sixth Annual Colorado Rare Plant Symposium: G2G3 Plants of North and Central Colorado. Symposium Minutes. Available on-line
    • Colorado Natural Heritage Program. 2012. Biodiversity Tracking and Conservation System. Colorado State University, Fort Collins, CO.
    • 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.
    • Flora of North America Editorial Committee, ed. (FNA). 1993+. Flora of North America North of Mexico. Oxford Univ. Press, New York, Oxford.
    • Johnson, R.L., M.R. Stevens, L.A. Johnson, M.D. Robbins, C.D. Anderson, N.J. Ricks, and K.M. Farley. 2016. Molecular and morphological evidence for Penstemon luculentus (Plantaginaceae): a replacement name for Penstemon fremontii var.glabrescens. PhytoKeys 63: 47-62. doi: 10.3897/phytokeys.63.7952
    • 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.
    • Lavender, A.E., M.M. Fink, S.E. Linn, D.M. Theobald. 2011. Colorado Ownership, Management, and Protection v9 Database. Colorado Natural Heritage Program and Geospatial Centroid, Colorado State University, Fort Collins, CO. (30 September).
    • 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.
    • 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.

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