Draba graminea
Author: Greene


San Juan draba


Brassicaceae (Mustard Family)

Close up of Draba graminea. Photo ©Al Schneider, www.swcoloradowildflowers.com.
Click image to enlarge.

Close up of Draba graminea. Photo ©Al Schneider, www.swcoloradowildflowers.com.
Click image to enlarge.
Close up of Draba graminea. Photo ©Al Schneider, www.swcoloradowildflowers.com.
Click image to enlarge.

Ranks and Status

Global rank: G2
State rank: S2
Federal protection status: None
State protection status: None

[+] Description and Phenology

Draba graminea: artwork in progress

General description: Draba graminea is a caespitose perennial herb, 1 to 5 cm tall. Stems are caulescent with slender unbranched hairs. Leaves are linear to linear-oblanceolate, glabrous except for long ciliate hairs on the lower half. These hairs are simple or sometimes forked. Cauline leaves are mostly absent; if present they number between one and six, and are reduced. The inflorescence is a raceme with three to 15 flowers subtended by leaf-like bracts. The petals are yellow and 4 to 5 mm long. The siliques are 5 to 10 mm long and 2 to 4 mm wide, elliptic-ovate, thick, and glabrous (Moore and Friedley 2004, Hitchcock 1941, Harrington 1954, Rollins 1993).Hitchcock 1941, Harrington 1954, Rollins 1993).

Look Alikes: There are morphological similarities in some Rocky Mountain members of Draba. Look-alike species include D. crassifolia , D. spectabilis, and D. exunguiculata. Draba graminea can be distinguished from the others by the ciliate, linear, basal leaves, the lack of cauline leaves, the leaf-like bracts subtending the flowers, and glabrous fruits (Flora of North America 2010, Moore and Friedley 2004).

Phenology: Flowers July-August (Colorado Natural Heritage Program 2012).

[+] Herbarium Photos

Images of Draba graminea housed at the Colorado State University Herbarium.

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Click image to enlarge.

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[+] Habitat

Habitat of Draba graminea by Peggy Lyon
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Habitat of Draba graminea by Peggy Lyon
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Draba graminea is a plant of the high mountains of southwestern Colorado. It is typically located in the alpine, and less often in subalpine areas. It occupies the crevices of rock outcrops, talus slopes, late snowmelt areas, and alpine tundra along the Continental Divide and the greater San Juan Mountains area (Moore and Friedley 2004). Associated species include Pseudocymopterus montanus, Silene acaulis, Parnassia fimbriata, Salix reticulata, Cilaria austromontana, Lidia obtusiloba, Luzula spicata, Geum rossii, Claytonia megarhiza, Artemisia scopulorum,  Potentilla diversifolia, Draba streptobrachia, Draba aurea, Draba crassifolia, Oreobrama pygmaea, Micranthes rhomboidea, Erigeron simplex, Rydbergii grandiflora, Artemisia scopulorum, Podistera eastwoodiae (Colorado Natural Heritage Program 2012).

Elevation Range: 9,600 - 13,684 feet (2,926 - 4,171 meters)

[+] Distribution

Distribution of Draba graminea in Colorado according to mapped land ownership/management boundaries (CNHP 2012, COMaP v9 ).
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Distribution of Draba graminea in Colorado
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Colorado endemic: Yes
Global range: Colorado endemic known from Dolores, Hinsdale, La Plata, Montezuma, Ouray, Rio Grande, San Juan, and San Miguel counties. Estimated range is 3,021 square kilometers (1,166 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 Draba graminea based on several ranking factors. This species was concluded to be “Effectively Conserved”. From Rondeau et al. 2011.
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Non-motorized recreation is considered to be the primary threat to the species at this time (Rondeau et al. 2011). Current threats to Draba graminea are difficult to discern due to the remoteness of the occurrences. The concern for the viability of the species is based on its limited abundance and restricted global distribution. Recreation, livestock grazing, and mining are likely to be the most influential activities with regards to D. graminea occurrences. Past threats that have been observed include erosion from nearby jeep trails and sheep grazing. Other potential threats to the species include extreme weather conditions, global warming, herbivory by native fauna (e.g. deer, elk, rodents, insects), competition from invasive species, and air pollution (Moore and Friedley 2004).

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 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.
    • Colorado Natural Heritage Program. 2012. Biodiversity Tracking and Conservation System. Colorado State University, Fort Collins, CO.
    • Flora of North America Editorial Committee. 2010. Flora of North America North of Mexico, Vol. 7, Magnoliophyta: Salicaceae to Brassicaceae. Oxford University Press, New York.
    • Harrington, H.D. 1954. Manual of the plants of Colorado. Sage Press, Chicago. 666 pp.
    • 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.
    • 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).
    • Moore, L. and S. Friedley. (2004, September 30). Draba graminea Green (Rocky Mountain draba): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/assessments/drabagraminea.pdf [March 2006].
    • 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.
    • Price, Robert. 1980. Personal communication with Robert Price 15 Oct. 1980.
    • Rollins, R.C. 1993. The Cruciferae of continental North America: Systematics of the mustard family from the Arctic to Panama. Stanford Univ. Press, Stanford, California. 976 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.
    • Schneider, A. 2013. Wildflowers, Ferns, and Trees of the Four Corners Regions of Colorado, New Mexico, Arizona, and Utah. Accessed on-line at http://www.swcoloradowildflowers.com.
    • 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

2012-12-12