Sclerocactus mesae-verdae
Author: (Boissevain ex Boissevain & C. Davids.) L. Benson

Mesa Verde cactus

Cactaceae (Cactus Family)

Close up Sclerocactus mesae-verdae courtesy of the Colorado Natural Areas Program
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Close up Sclerocactus mesae-verdae by Steve O'Kane
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Close up Sclerocactus mesae-verdae courtesy of The Nature Conservancy
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Ranks and Status

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

[+] Description and Phenology

Sclerocactus mesae-verdae by Ann Fleming
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General description: Stems pale green or gray-green, nearly globose in outline, usually occurring singly, but sometimes in clumps of up to 10 individuals; single plants mostly 3.8-6.2 cm high, some 17.5 cm high; usually 8-10 small radial spines at tops of conical tubercles; at maturity, tubercles coalesce into 13-17 ribs; flowers and fruit at top of plants; flowers yellow to cream, 2.5-3.1 cm in diameter; fruit green, becoming tan, 4.5-5 mm long, dehiscent irregularly transverse above middle; seeds 2 mm long, 3 mm broad.

Look Alikes: Not likely to be confused with other taxa in the area (Spackman et al. 1997).

Phenology: Flowers mid-April through mid-May; fruit May-June (Spackman et al. 1997).

[+] Habitat

Habitat of Sclerocactus mesae-verdae by Karin Decker
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Habitat of Sclerocactus mesae-verdae by Karin Decker
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Dry, exposed hillsides of Mancos/Fruitland adobe clay badlands; usually on gentle slopes, badlands. SW side of hills in adobe soil. Occurs only on alkaline soil (O'Kane 1987). Often occurs with Atriplex corrugata, A. gardneri, Eriogonum inflatum, Stanleya pinnata, and Phacelia splendens (Colorado Natural Heritage Program). 

Elevation Range: 5,046 - 5,771 feet (1,538 - 1,759 meters)

[+] Distribution

Distribution of Sclerocactus mesae-verdae in Colorado.
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Colorado endemic: No
Global range: Occurs only in parts of Montezuma County, Colorado and San Juan County, New Mexico. Mostly on Navajo Indian Reservation lands (Roth, pers. comm., 1998).
State range: Known from Montezuma County in Colorado. Estimated range in Colorado is 84 square kilometers, calculated in GIS by the Colorado Natural Heritage Program in 2008 by drawing a minimum convex polygon around the known occurrences. Also known from New Mexico.

[+] Threats and Management Issues

Summary results of an analysis of the status of Sclerocactus mesae-verdae based on several ranking factors. This species was concluded to be "under conserved”. From Rondeau et al. 2011.
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The primary threats at this time are considered to be collecting and insect herbivory (Rondeau et al. 2011). It is not known if all of the occurrences are or are not threatened by these activities. Collection of cactus plants and seeds continues to represent the greatest threat to the Mesa Verde cactus (Coles 2003). Energy development, potential oil and gas drilling, pipeline construction, mining, development, off-road vehicles, and trampling by livestock also pose threats to the species (O'Kane 1988).

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Benson, L. 1982. The Cacti of the United States and Canada. Stanford University Press, Stanford, California. 1044 pp.
    • Benson. L. 1966. A revision of Sclerocactus. Cactus and Succulent Jouranl of America 38:54-55
    • Biosystems Analysis, Inc. 1981. Biological assessments of the black-footed ferret and the mesa-verde cactus in connection with the Ute Mountain Ute Strip Coal Mine. San Fransisco, ca 94105.
    • Boissevain, C. and C. Davidson. 1940. Colorado Cacti: An Illustrated Guide Describing All of the Native Colorado Cacti. Abbey Garden Press, Pasadena, CA.
    • Coles, J. 2003. Project description for "Population Biology and Habitat Protection of Sclerocactus mesae-verdae".
    • Coles, J.J, K.L. Decker, and T.S. Naumann. 2010. Ecology and Population Dynamics of Sclerocactus mesae-verdae (Boiss. & Davidson) Benson.
    • Flora of North America Editorial Committee. 2003. Flora of North America North of Mexico. Vol. 4, Magnoliophyta: Caryophyllidae, part 1. Oxford University Press, New York. 559 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.
    • Kass, R. 2001a. Demographic monitoring of Wright fishook cactus. In: Maschinski, Joyce; Holter, Louella, tech. eds. 2001. Southwestern rare and endangered plants: Proceedings of the Third Conference; 2000 September 25-28; Flagstaff, AZ. Proceedings RMRS-P-23. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 250 pp. Accessed online on 5/17/2011 at:
    • Knight, P.J. 1981. Unpublished report on Sclerocactus mesae-verdae. 47 pp.
    • 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. 1988. Colorado's Rare Flora. Great Basin Naturalist. 48(4):434-484.
    • O'Kane, S.L. 1987. Population biology of Sclerocactus mesae-verde. Unpublished report.
    • Peterson, S.J. 1982. Threatened and endangered plants of Colorado. U.S. Fish and Wildlife Service, Denver, CO. 35 pp.
    • 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.
    • Roth, Daniela. October 17, 1998. Personal communication to Martha Martinez through electronic mail: plants endemic or mostly ocurring in Navajo Nation lands. Botanist for the Navajo Nation Heritage Program.
    • Schneider, A. 2013. Wildflowers, Ferns, and Trees of the Four Corners Regions of Colorado, New Mexico, Arizona, and Utah. Accessed on-line at
    • Sivinski, R., and K. Lightfoot, eds. 1995. Inventory of rare and endangered plants of New Mexico. 3rd edition. Miscellaneous Publication No. 4, Forestry Division, New Mexico Energy, Minerals and Natural Resources Dept., Santa Fe.
    • 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.
    • Tonne, P. 2003. Personal communication with Colorado Natural Heritage Program staff.
    • U. S. Fish and Wildlife Service. 1984. Mesa Verde Cactus Recovery Plan. U. S. Fish and Wildlife Service, Albuquerque, New Mexico 63 pp.
    • USDA, NRCS. 2013. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
    • Wagner, W.L., and D. Sabo. No date. Status report for Sclerocactus mesae-verdae. Unpublished report.
    • 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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