Townsendia rothrockii
Author: Gray ex Rothrock

Rothrock townsend-daisy

Asteraceae (Sunflower Family)

Close up of Townsendia rothrockii by Peggy Lyon
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Close up of Townsendia rothrockii by Lori Brummer
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Close up of Townsendia rothrockii by Lori Brummer
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Taxonomic Comments

Distinctions between Townsendia glabella and T. rothrockii are subtle. Types of the two names are probably better considered to be conspecific (Flora of North America 1993+).

Ranks and Status

Global rank: G2G3
State rank: S2S3
Federal protection status: None
State protection status: None

[+] Description and Phenology

Townsendia rothrockii: artwork in progress

General description: Townsendia rothrockii  plants are perennials, with stems more or less erect, and 1-3 cm long. Plants are glabrous or somewhat strigose. Leaves are basal and cauline, spatulate to oblanceolate, 10-35 × 2-7 mm, and fleshy. Heads are sessile or on peduncles. Involucres are hemispheric, and 12-28+ mm in diameter. Phyllaries are 40-60+ in (3-)4-5+ series, obovate to oblanceolate, 7-9+ mm long, and the apices are obtuse to acute. Ray florets are 18-40; and are blue to purplish (Flora of North America 2006).

Look Alikes: Townsendia rothrockii has succulent leaves, and phyllaries that are obovate, ovate, or broadly lanceolate. Townsendia glabella does not have succulent leaves and the phyllaries are lanceolate and acute (Weber and Wittmann 2012). Involucre bracts of T. rothrockii are usually reddish-purple and anthocyanic throughout (Ackerfield 2012).

Phenology: Flowers June-August (Ackerfiled 2012, Colorado Natural Heritage Program 2012).

[+] Herbarium Photos

Images of Townsendia rothrockii housed at the Colorado State University Herbarium.

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[+] Habitat

Habitat of Townsendia rothrockii by Peggy Lyon
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This species has been reported growing in alpine fellfields, krummholtz, subalpine meadows, oak brush, grasslands, shrub/herbaceous areas, talus slopes, forest openings, high plateau ridgetops, mountain passes, late-snow and cornice areas, limestone outcrops, rocky streamsides, disturbed mine and roadside areas, bare sandstone slopes, lava cliffs, and summit ridges (Beatty et al. 2004).  Associated species include Abies lasiocarpa, Agrostis thurberiana, Anemone multifida, Draba nivalis var. exigua, Eritrichium aretioides, Festuca thurberi, Frageria spp., Frasera spp., Juniperus spp., Oreoxis alpina, Physaria spp., Pinus spp., Pinus ponderosa, Polemonium viscosum, Populus spp., Quercus spp., Rydbergia grandiflora, Shepherdia spp., Stipa spp., Trifolium dasyphyllum, Trifolium nanum, and Valeriana capitata (Beatty et al. 2004).

Areas above timberline that retain snow into summer. Also high plateau ridgetops in openings in ponderosa pine (Pinus ponderosa) forest. 2440-4115 m elevation.

Elevation Range: 7,923 - 13,218 feet (2,415 - 4,029 meters)

[+] Distribution

Distribution of Townsendia rothrockii in Colorado according to mapped land ownership/management boundaries (CNHP 2012, COMaP v9 ).
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Distribution of Townsendia rothrockii in Colorado
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Colorado endemic: Yes
Global range: Colorado endemic, known from thirteen counties, in central and southwestern Colorado. New Mexico reports are apparently false (Beatty et al. 2004). Colorado herbaria have 23 specimens from 10 Colorado counties. Estimated range of the 14 occurrences in the CNHP database is 25,365 square kilometers (9,793 square miles), calculated in GIS by drawing a minimum convex polygon around the occurrences (Colorado Natural Heritage Program 2008)

[+] Threats and Management Issues

Summary results of an analysis of the status of Townsendia rothrockii based on several ranking factors. This species was concluded to be “Effectively 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). Possible human-related threats to T. rothrockii include motorized and non-motorized recreation, road and structure construction, erosion and sedimentation related to roads, grazing activities, exotic species invasion, small-scale mining, and any changes to natural disturbance regimes. The extent of these activities near existing populations of T. rothrockii is unknown. Environmental and biological threats to populations of T. rothrockii include succession, environmental fluctuations, herbivory, genetic isolation, inadequate pollination, global climate changes, and changes to the natural disturbance regime (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. Townsendia rothrockii Gray ex Rothrock (Rothrock's Townsend daisy): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Available
    • Colorado Natural Heritage Program. 2008. The Fifth Annual Colorado Rare Plant Symposium: G2 Plants of Colorado. Symposium Minutes. Available on-line
    • Colorado Natural Heritage Program. 2012. Biodiversity Tracking and Conservation System. Colorado State University, Fort Collins, CO.
    • Flora of North America Editorial Committee, ed. (FNA). 1993+. Flora of North America North of Mexico. Oxford Univ. Press, New York, Oxford.
    • Flora of North America Editorial Committee. 2006. Flora of North America North of Mexico. Vol. 20. Magnoliophyta: Asteridae, part 7: Asteraceae, part 2. Oxford Univ. Press, New York. xxii + 666 pp.
    • 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).
    • 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.
    • Rickett, H. W. 1973. Wild flowers of the United States: Vol. 6 (3 parts). The central mountains and plains. McGraw-Hill Book Company, New York. 784 pp. + plates.
    • 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
    • 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.

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