Phacelia formosula
Author: Osterhout


North Park phacelia


Hydrophyllaceae (Waterleaf Family)

Close up of Phacelia formosula by Susan Spackman Panjabi
Click image to enlarge.

Ranks and Status

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

[+] Description and Phenology

Please see 1997 profile.

General description: Herbaceous biennial up to 22 cm tall; much branched, erect to spreading. Inflorescence is a helicoid cyme. Flowers are purple, stamens and styles are exserted. Leaves are pinnately dissected, lancelotate or elliptical. Plants appear somewhat grayish; gladular and hursute (Spackman et al. 1997).

Look Alikes: Species cannot be confused on site (Wiley-Eberle 1979), it is distinctive in rosette and flowering forms (pers. comm. Coles 1994). P. formosula appears to be most closely related to P. glandulosa, but can be distinguished from that species by its usually much-branched, erect to spreading habit, less exserted stamens and style, darker seeds, narrower calyx lobes, and more pubescence style (Peterson 1986). P. glandulosa is allopatric, growing on oil shale (Coles pers. comm. 1994).

Phenology: Flowering late June occassionally through October in favorable years. In fruit July through November (Coles pers. comm. 1994). Flowering in July to early August and fruiting in August (Wiley-Eberle 1979). Plants bloom from late June to early October (Warren 1990).

[+] Habitat

Habitat of Phacelia formosula by Jill Handwerk
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Poorly vegetated exposures of the Coalmont Formation.  Steep-sided ravines, low sandy hills and bluffs (Spackman et al. 1997).  Associated taxa include: ChrysothamnusArtemisiaOryzopsis hymenoides, Chaenactis douglasii, Gilia pinnatifida, Ipomopsis congesta, Stipa sp., Tetradymia canescensEriogonum exilifolumE. umbellatumE. pauciflorumE. cernuumArtemisia frigidaLupinus sp., Astragalus kentrophytaOpuntia polyacantha and Comandra.

Elevation Range: 7,933 - 8,287 feet (2,418 - 2,526 meters)

[+] Distribution

Distribution of Phacelia formosula in Colorado.
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Colorado endemic: Yes
Global range: Known from Jackson County, Colorado. The species is found within about 145 square miles in North Park, Jackson County.  

[+] Threats and Management Issues

Summary results of an analysis of the status of Phacelia formosula based on several ranking factors. This species was concluded to be "weakly conserved”. From Rondeau et al. 2011.
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Motorized recreation is considered to be the primary threat to the species (Rondeau et al. 2011). Habitat is susceptible to erosion. Frequently used motorcycle trails and dirt roads from the airport to the campground have been documented to disturb the plants. 10 to 15 plants were reportedly lost at the State Natural Area in North Park (CNHP 2004). Other threats include livestock trampling/ trailing, grazing, and coal, oil and gas development.

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Atwood, D. 2010. Progress Report for Phacelia formosula Osherhout in North Park, Jackson County, Colorado and the Scully Phacelia in Larimer County, Colorado; prepared for USFWS.
    • Coles, Janet. 2004. Field Visit to Phacelia formosula in North Park and Phacelia sp. in Larimer County. unpublished notes on field visit of August 7, 2004.
    • Colorado Native Plant Society. 1989. Rare plants of Colorado. Rocky Mountain Nature Association, Colorado Native Plant Society, Estes Park, Colorado. 73 pp.
    • Colorado Natural Heritage Program. 2006. Biological Conservation Datasystem. Colorado State University, Ft. Collins, CO.
    • 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.
    • O'Kane, S.L. 1986. Endangered Species Information System Species Workbook Part VII. Unpublished report for the US Fish and Wildlife Service, Denver, CO.
    • Peterson, J. S. and K.L. Wiley-Eberle. 1986. North Park Phacelia Recovery Plan. USFWS, Denver, CO. 28pp.
    • Peterson, J. Scott and K.L. Wiley-Eberle. 1986. North Park Phacelia Recovery Plan. USFWS, Denver, CO. 28pp.
    • 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.
    • U. S. Fish and Wildlife Service. 1982. Determination that Phacelia formosula is an endangered species. Federal Register 47(170): 38540-38543.
    • USDA, NRCS. 2013. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
    • Warren, K.D. 1990. A Comparative Study of the Reproductive Biology of a Rare and a Common Phacelia Species. Unpublished thesis.
    • 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.
    • Wiley-Eberle, K.L. 1979. Status report for Phacelia formosula. Unpublished report prepared for the Bureau of Land Management.

Last Updated

2015-03-12