Physaria pruinosa
Author: Greene


Pagosa bladderpod


Brassicaceae (Mustard Family)

Close up Physaria pruinosa by Sara Brinton
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Close up Physaria pruinosa by Steve O'Kane
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Close up Physaria pruinosa by Janis Huggins
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Close up Physaria pruinosa by Peggy Lyon
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Ranks and Status

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

[+] Description and Phenology

Physaria pruinosa by Mary Clark. Please also see 1997 profile.
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General description:

Look Alikes: None (pers. comm. Minton and Spackman, 1994).

Phenology: Physaria pruinosa begins to flower by mid May with fruiting time depending on elevation. Plants at lower elevations are in late stages of fruiting by the beginning of June, whereas plants at higher elevations are only in early stages of fruiting at that time (Rouse 1981). Plants have been observed with a few flowers as late as the last week of August (Anderson 1988).

[+] Habitat

Habitat of Physaria pruinosa by Peggy Lyon
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Physaria pruinosa occurs on Mancos Shale, open clay barrens surrounded by montane grasslands, sometimes in open Pinus ponderosa stands with Quercus gambelii, it can also be associated with Douglas fir and Englemann spruce communities at the upper limits of its range (Rouse 1981). Commonly associated species include: Pinus ponderosa, Quercus gambellii, Mahonia repens, Commandra umbellatum, Townsendia glabella, Astragalus lonchocarpus, and Penstemon linarioides (Anderson 1988).

Elevation Range: 6,827 - 8,507 feet (2,081 - 2,593 meters)

[+] Distribution

Distribution of Physaria pruinosa in Colorado.
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Colorado endemic: No
Global range: Known from southern Colorado (Archuleta County, and the extreme southern portion of Hinsdale County) and northern New Mexico (Rio Arriba County). Estimated range is at least 588 square kilometers (227 square miles), calculated in 2008 by the Colorado Natural Heritage Program in GIS by drawing a minimum convex polygon around the Colorado occurrences. The New Mexico location needs to be added to this range calculation.
State range: Known from southern Colorado (Archuleta County, and the extreme southern portion of Hinsdale County). Estimated range in Colorado is at least 588 square kilometers (227 square miles), calculated in GIS by drawing a minimum convex polygon around the occurrences. Also known from northern New Mexico (Rio Arriba County).

[+] Threats and Management Issues

Summary results of an analysis of the status of Physaria pruinosa based on several ranking factors. This species was concluded to be “moderately conserved”. From Rondeau et al. 2011.
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Residential and commercial developments are considered to be the primary threats to the species at this time (Rondeau et al. 2011). The city of Pagosa Springs lies within the plant's range. Residential growth, development of resort homes, and increased tourism due to the development of a proposed ski resort 20 miles east of Pagosa Springs threaten occurrences. Archuleta County is one of the fastest growing counties in the United States, and future land use plans that have been drafted by Archuleta County do not include adequate provisions for the protection of P. pruinosa (Anderson 2006).

Populations in the Piedra Valley may be vulnerable to the effects of livestock grazing. Though cattle pose a minimum threat of grazing the plants (they contain chemicals which render the plants unpalatable), cattle grazing tends to promote erosion and up-rooting where plants occur on slopes by severely disturbing the soil (Anderson 1988). These populations are at risk mainly where cattle trails traverse the shale barrens (Neely 1990).

Physaria pruinosa is also threatened by off-road vehicle recreation, other recreational activities, energy resource development, exotic species invasions, use of herbicides and pesticides for weed management and range improvement, effects of small population size, prairie dog herbivory, fire, global climate change, and pollution (Anderson 2006).

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Al-Shehbaz, I. A., and S. L. O'Kane. 2002. Lesquerella is united with Physaria (Brassicaceae). Novon 12:319-329.
    • Anderson, D.G. (2006, August 29). Lesquerella pruinosa Greene (Pagosa bladderpod): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/assessments/lesquerellapruinosa.pdf [January 2007].
    • Anderson, J.L. 1988. Status report for Lesquerella pruinosa. Unpublished report prepared for the U.S. Fish and Wildlife Service, Golden, Colorado.
    • Anonymous. 1990. Endangered Species Technical Bulletin. 15(10):11.
    • Carpenter, A. T. 1992. Conversation with Alan Carpenter. The Nature Conservancy, Colorado Field Office, Boulder, Colorado. January 27, 1992.
    • Colorado Native Plant Society. 1989. Rare plants of Colorado. Rocky Mountain Nature Association, Colorado Native Plant Society, Estes Park, Colorado. 73 pp.
    • Ecology Consultants, Inc. 1978. An illustrated guide to the proposed threatened and endangered plant species in Colorado. U.S. Fish and Wildlife Service, Lakewood, CO. 114 pp.
    • Ferson, S. 1990. RAMAS stage users manual. Applied Biomathematics, 100 N. County Rd., Setauket, NY 11733.
    • Heil, K.D., S.L. O'Kane Jr., L.M. Reeves, and A. Clifford, 2013. Flora of the Four Corners Region, Vascular Plants of the San Juan River Drainage; Arizona, Colorado, New Mexico, and Utah. Missouri Botanical Garden Press, St. Louis, Missouri. 1098 pp.
    • Jakubos, B. 1985. A comparison of Lesquerella pruinosa densities under varying habitat site factors. Unpublished report on file at The Nature Conservancy, Colorado Field Office, Boulder, 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.
    • Neely, B. 1990. Preserve design for Piedra Valley. Unpublished report on file at The Nature Conservancy, Colorado Field Office, Boulder, 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. 1988. Colorado's Rare Flora. Great Basin Naturalist. 48(4):434-484.
    • Payson, E. B. 1921. Monograph of the genus Lesquerella. Annals of the Missouri Botanical Garden, 8:103-236.
    • Rollins, R.C. 1983. Studies in the Cruciferae of western North America. J. Arnold Arboretum 64(4): 491-501.
    • Rollins, R.C., and E.A. Shaw. 1973. The genus Lesquerella (Cruciferae) in North America. Harvard Univ. Press. Cambridge, MA. 288 pp.
    • 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.
    • Rouse, L. 1981. Element stewardship abstract for Lesquerella pruinosa. Unpublished report prepared for the Nature Conservancy, Colorado Field Office, Boulder, CO.
    • 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. 1988. Proposal to determine Astragalus osterhoutii and Penstemon penlandii to be endangered species. Federal Register 53(128): 25181-25185.
    • 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.
    • 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

2014-06-26