Camissonia eastwoodiae
Author: (Munz) Raven


Eastwood evening-primrose


Onagraceae (Evening Primrose Family)

Close up of flower of Camissonia eastwoodiae by Janis Huggins
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Close up of Camissonia eastwoodiae by Peggy Lyon
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Taxonomic Comments

= Chylismia eastwoodiae (Ackerfield 2012).

Ranks and Status

Global rank: G2
State rank: S1
Federal protection status: BLM Sensitive
State protection status: None

[+] Description and Phenology

Camissonia eastwoodiae: artwork in progress

General description: Annual herbs from taproots.  Stems simple or branched near the base, 40-60 cm tall (Welsh  al. 1993).  Flowers are bright yellow with reddish streaks.  Plants have reddish stems, and dark green leaves.  Petals are usually more that 6 mm long, and are capsules on well-defined pedicles (Weber and Wittmann 2012).

Look Alikes: At maturity, Camissonia eastwoodiae stigma are held well above the anthers, and the petals are more than 6 mm long. In contrast, Camissonia scapoidea stigma are surrounded by the anthers at maturity, and petals are less than 5.5. mm long (Weber and Wittmann 2012).

Phenology: Flowers May-June (Ackerfield 2012, Colorado Natural Heritage Program 2012).

[+] Herbarium Photos

Images of Camissonia eastwoodiae housed at the Colorado State University Herbarium.

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[+] Habitat

Habitat of Camissonia eastwoodiae by Peggy Lyon
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Habitat of Camissonia eastwoodiae by Peggy Lyon
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In Colorado this species is found on clay soils derived from Mancos shale with Atriplex gardneri a dominant associate. Other associated species include Eriogonum inflatum, Phacelia crenulata, Acrolasia albicaulis, Tetradymia spinosa, Cymopterus bulbosa, Calochortus nuttallii, Sphaeralcea parvifolia, Oenothera caespitosa ssp. marginata, Corispora tenella, Eriastrum diffusum, Opuntia polyacantha, Atriplex corrugata, Xylorhiza venusta, Hilaria jamesii, and Oryzopsis hymenoides (Colorado Natural Heritage Program 2012).


Elevation Range: 4,567 - 6,050 feet (1,392 - 1,844 meters)

[+] Distribution

Distribution of Camissonia eastwoodiae in Colorado according to mapped land ownership/management boundaries (CNHP 2012, COMaP v9 ).
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Distribution of Camissonia eastwoodiae in Colorado
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Colorado endemic: No
Global range: Endemic to the Colorado Plateau. Found in Utah (seven counties), Arizona (2 counties), and Colorado (2 counties) (USDA NRCS 2012).
State range: Known from Delta and Mesa counties in Colorado. Estimated range in Colorado is 545 square kilometers (210 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 Camissonia eastwoodiae based on several ranking factors. This species was concluded to be “Weakly Conserved”. From Rondeau et al. 2011.
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The primary threat at this time is considered to be roads and ORVs (Rondeau et al. 2011). It is not known if all of the occurrences are or are not threatened by these activities. At least one occurrence is within the BLM Colorado Canyons National Conservation Area with a management plan in progress. There are some oil and gas wells nearby the area as well as roads, grazing, and weedy areas. The primary threat is presumed to be surface disturbance. Little data is available on the threats to this species. Its low numbers make it important to continue inventory efforts and determine the possible threats and appropriate management issues.

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Albee, B.J., L.M. Shultz, and S. Goodrich. 1988. Atlas of the vascular plants of Utah. Utah Museum Natural History Occasional Publication 7, Salt Lake City, Utah. 670 pp.
    • Colorado Natural Heritage Program. 2008. The Fifth Annual Colorado Rare Plant Symposium: G2 Plants of Colorado. Symposium Minutes. Available on-line http://www.cnhp.colostate.edu/teams/botany.asp#symposia.
    • 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.
    • 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.
    • Kartesz, J.T. 1996. Species distribution data at state and province level for vascular plant taxa of the United States, Canada, and Greenland (accepted records), from unpublished data files at the North Carolina Botanical Garden, December, 1996.
    • 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.
    • 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.
    • 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.
    • Weber, W.A., and R.C. Wittmann. 2012b. Colorado Flora, Western Slope, a field guide to the vascular plants, fourth edition. Boulder, Colorado. 532 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.

Last Updated

2013-02-13