Penstemon degeneri
Author: Crosswhite


Degener beardtongue


Scrophulariaceae (Figwort Family)

Close up of Penstemon degeneri by Steve Olson
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Close up of Penstemon degeneri by Steve Olson
Click image to enlarge.
Close up of Penstemon degeneri by Steve Olson
Click image to enlarge.
Close up of Penstemon degeneri by Steve Olson
Click image to enlarge.

Ranks and Status

Global rank: G2
State rank: S2
Federal protection status: USFS Sensitive, BLM Sensitive
State protection status: None

[+] Description and Phenology

Artwork in progress by Sharon Garrett. Please also see 1997 profile.

General description: Penstemon degeneri is a perennial herb from 25 to 40 cm tall with five or more, slender (1.0 to 2.5 mm diameter at base), leafy, short-pubescent stems and a suffrutescent caudex. The basal leaves are lanceolate, entire, and up to 6 cm long and 16 mm wide (Spackman et al. 1997). The cauline leaves are more linear, more pubescent, and more sessile. The unleafy, sparingly glandular inflorescence is 3 to 10 cm high, with 2 to 10 tubular flowers at the ends of the stems. The dark blue to violet corolla of the flower is gradually inflated, 14 to 19 mm long and 4 to 5 mm wide at the mouth. The corollas are slightly two-ridged on the floor and have straight, reddish guidelines and sparse yellow hairs in the corolla throat. The staminode is also bearded with sparse golden hairs for about half its length. The anther sacs are 2.0 mm across the connective and are longer than wide. The papery calyx is persistent and the dehisced capsules are 7 to 9 mm long, with small, dark brown, irregularly angled seeds (Beatty et al. 2004).

Look Alikes: Penstemon degeneri is similar to P. radicosus in appearance, though P. radicosus is limited to Jackson County in northcentral, Colorado, and P. degeneri is found in southcentral Colorado. Penstemon griffinii is the only relative in the alliance in Colorado. It is characterized by having a deeply 2-ridged corolla and a dense covering of long, golden hairs on the floor and opening of the corolla and staminode. Penstemon degeneri has a less strongly ridged corolla and an opening with a few hairs and a glabrous floor. The staminode has an orange beard (Peterson and Harmon 1981). Penstemon griffinii has a basal rosette through the flowering period, and smaller, linear stem leaves (2-3 cm long, 2 mm wide), while Penstemon degeneri lacks a basal rosette at flowering time, and has longer and wider stem leaves (up to 6 cm long and 16 mm wide, Spackman et al. 1997). Penstemon griffinii has dense golden hairs in its corolla throat, while P. degeneri has sparser white to light yellow hairs. (Caution: both species have dense golden yellow hairs on the staminode which may be confused with hairs on the corolla itself).

Phenology: Flowering occurs June through mid July, and fruits set late July (Spackman et al. 1997).

[+] Habitat

Habitat of Penstemon degeneri by Dave Elin
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Habitat of Penstemon degeneri by Dave Elin
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This species is found in open pinyon-juniper woodlands and montane grasslands, in rocky soils with igneous bedrock.  The plants grow mainly near the rim of canyons, and also in cracks of large rock slabs, in full sun or shade.  Associated species include Quercus gambelii, Sitanion longifolium, Verbena bacteata, Lesquerella montana, Grindelia squarrosa, Heterotheca horrida, Artemisia frigida, Carex stenophylla, Eriogonum jamesii, Opuntia phaeacantha, Atriplex canescens, Pinus edulis, and Juniperus monosperma (Peterson and Harmon 1981).

Elevation Range: 5,991 - 9,449 feet (1,826 - 2,880 meters)

[+] Distribution

Distribution of Penstemon degeneri in Colorado.
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Colorado endemic: Yes
Global range: A Colorado endemic, this species is known from Fremont, and Custer counties. Estimated range is 2,445 square kilometers (944 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 degeneri based on several ranking factors. This species was concluded to be “moderately conserved”. From Rondeau et al. 2011.
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Motorized recreation is considered to be the primary threat to the species at this time (Rondeau et al. 2011). Penstemon degeneri is vulnerable because of its restricted geographic range, the small number of documented occurrences, and its vulnerability to human-related and environmental threats. Disturbances and land management activities may maintain suitable habitat for this species or negatively impact existing populations, depending on the disturbance intensity, frequency, and type. Threats to the long-term persistence of P. degeneri populations or habitats likely differ for each of the occurrences. The most significant threats to the occurrences on National Forest System lands include motorized and non-motorized recreation, non-native plant invasion, grazing and trampling, extensive herbivory, succession, and global environmental changes. Populations near roads, trails, or campgrounds are at higher risk for the detrimental effects of road or trail associated activities and non-native plant invasion (Beatty et al. 2004).

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Beatty, B.L., W.F. Jennings, and R.C. Rawlinson (2004, February 23). Penstemon degeneri Crosswhite (Degeners beardtongue): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/assessments/penstemondegeneri.pdf.
    • Colorado Native Plant Society. 1989. Rare plants of Colorado. Rocky Mountain Nature Association, Colorado Native Plant Society, Estes Park, Colorado. 73 pp.
    • Crosswhite, F.S. 1965. Revision of Penstemon section Penstemon (Scrophulariaceae) II. A western alliance in series Graciles. American Midland Naturalist 74:429.
    • 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.
    • Peterson, J.S. and W. Harmon. 1981. Status report on Penstemon degeneri. Unpublished report prepared for the Colorado Natural Areas Program, Denver, CO.
    • 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.
    • 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, Eastern Slope, A Field Guide to the Vascular Plants, Fourth Edition. Boulder, Colorado. 555 pp.

Last Updated

2013-10-30