Nuttallia speciosa
Author: Osterhout

Jeweled blazingstar

Loasaceae (Blazingstar Family)

Close up of Nuttallia speciosa by Stephanie Neid
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Close up of Nuttallia speciosa by Stephanie Neid
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Taxonomic Comments

= Mentzelia speciosa. This taxon is treated by Ackerfield (2012) as Mentzelia speciosa var. speciosa. The taxon formerly treated as M. sinuata is now treated as M. speciosa var. sinuata (Ackerfield 2012). Weber and Wittmann (2012) lump Nuttallia chrysantha, N. densa, N. reverchonii, N. sinuata, and N. speciosa all under Nuttallia multiflora, noting that further study is needed.

Ranks and Status

Global rank: G3
State rank: S3
Federal protection status: None
State protection status: None

[+] Description and Phenology

Nuttallia speciosa by Heidi Snyder
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General description: Herbaceous perennial or biennial, 3-5 dm tall, with bright yellow flowers.  Stems are white, slender to stout, and branched.   Leaves usually do not have a broad and clasping base.  The outer fertile stamens have broad filaments, grading to inner stamens with narrow filaments.  Seeds are smooth in appearance at 10X (Ackerfield 2012).  Characteristic of the Blazingstar Plant Family, the leaves are covered with hairs that adhere to clothing or fur like velcro. 

Look Alikes: Mentzelia nuda plants are taller and more stout, and have white to light yellow flowers. Mentzelia speciosa flowers are bright yellow.

Phenology: Flowers May through early September, and fruit in August and September (Colorado Natural Heritage Program 2012) .

[+] Herbarium Photos

Images of Nuttallia speciosa housed at the Colorado State University Herbarium.

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[+] Habitat

Habitat of Nuttallia speciosa: not available

The habitat for this species has not been clearly defined. Many of the occurrences are found in sandy soils derived from granitic parent materials within pinyon-juniper woodlands. Plants have also been documented in gravel and ash soils, and in association with Ponderosa pine, Douglas fir, and Gambel's oak (Colorado Natural Heritage Program 2012).

Elevation Range: 5,387 - 10,853 feet (1,642 - 3,308 meters)

[+] Distribution

Distribution of Nuttallia speciosa in Colorado according to mapped land ownership/management boundaries (CNHP 2012, COMaP v9 ).
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Distribution of Nuttallia speciosa in Colorado: please see county list under State Range

Colorado endemic: No
Global range: Known from Colorado and Wyoming (USDA NRCS 2012). Known from fourteen counties in Colorado (UDSA NRCS 2012) and one location in Wyoming (Atlas of the Flora of Wyoming 1996).
State range: Known in Colorado from the following counties: Arapaho, Boulder, Chaffee, Clear Creek, Denver, Douglas, El Paso, Fremont, Gilpin, Jefferson, Larimer, Mineral, Saguache, Teller (Univerisity of Colorado Herbarium, UDSA NRCS 2012).

[+] Threats and Management Issues

The primary threats are from residential development, road maintenance, and recreation activities. Many occurrences are found in disturbed areas such as road cuts (Colorado Natural Heritage Program 2012).

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Atlas of the Flora of Wyoming. 1996. Rocky Mountain Herbarium, University of Wyoming. Accessed on-line at
    • Colorado Natural Heritage Program. 2007. The Fourth Annual Colorado Rare Plant Symposium: G2 and G3 Plants of Northeast Colorado. Symposium Minutes. Available on-line
    • Colorado Natural Heritage Program. 2012. Biodiversity Tracking and Conservation System. Colorado State University, Fort Collins, CO.
    • Harrington, H.D. 1954. Manual of the plants of Colorado. Sage Press, Chicago. 666 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).
    • USDA, Natural Resources Conservation Service, PLANTS Database [USDA PLANTS]. Accessed 2007.
    • 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.

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