Uinta Basin Hookless Cactus

Sclerocactus glaucus

Description

A leafless, succulent plant, the stubby Uinta Basin hookless cactus, Sclerocactus glaucus, has one or several spherical stems 1.6-2.4 in (4-6 cm) long and about 2 in (5 cm) in diameter, usually with twelve ribs. Spines are dense, relatively long, and overlap to obscure the stem. The central spines are 1 in (2.5 cm) long; the lower central spine is not hooked but sometimes curves. The straight radial spines are white or brown, numbering six to eight spines per cluster, spreading in a circle. The purplish red flower is about 2 in (5 cm) in diameter; the sepals have lavender midribs and pink margins. From a distance, the white and brown spines covering the green ribs give the cactus a gray-green appearance. This color blends with the background rocks, making the cactus hard to locate.

This species of cactus has been known by a confusing variety of scientific names: Echinocactus glaucus, E. subglaucus, E. whipplei var. glaucus, Pediocactus glaucus, Sclerocactus franklinii, and S. whipplei var. glaucus.

Habitat

Uinta Basin cactus is found on hills and mesas in or near desert areas of the Colorado Plateau in alluvial soils at 4,600-6,900 ft (1,400-2,100 m) elevation.

Distribution

Uinta Basin hookless cactus is endemic to the semi-arid plateau region of northeastern Utah and northwestern Colorado, west and south of the Uinta Mountains. It is found at only three population centers, two in Colorado and one in Utah. As of 1990, the species had a documented population of about 22,000 individuals. The Uinta Basin of northeastern Utah hosts a major population center with three important population groups, one on alluvial river terraces near the confluence of the Green, White and Duchesne Rivers, another along the base of the Badlands Cliffs in southeastern Duchesne County, and a small third population of a morphologically distinct form growing on the clay badlands.

In western Colorado, the cactus occurs in two major population centers in the upper Colorado and Gunnison River valleys. One of these is on the alluvial river terraces of the Gunnison River from near Delta, Colorado, to southern Mesa County, Colorado; and the other is on alluvial river terraces of the Colorado River and in the Plateau and Roan Creek drainages in the vicinity of De Beque, Colorado.

The majority of the species' range is on federal land managed by the Bureau of Land Management (BLM), with important populations on Fish and Wildlife Service (FWS) lands (at the Ouray National Wildlife Refuge), Department of Energy lands (at the Naval Oil Shale Reservoir #2), and on Indian lands (Ute Tribe, Uintah and Ouray Reservation). Private land on which the species occurs is primarily near De Beque, Colorado.

Threats

Despite the plant's natural camouflage and scattered distribution, its greatest nemesis is the collector. Because of its rarity and the beauty of its flower, this cactus is highly prized by both amateur gardeners and plant dealers. Botanists have encouraged artificial propagation of the plant for sale to the commercial market, in order to spare the wild population.

Much of the habitat area has been targeted for oil and gold exploration, and the local development of energy and water resources also threatens the habitat. Since the cactus has been listed as Endangered, the BLM must now consult with the FWS when activities such as these are planned on federal land. Such activities must be regulated to benefit the cactus whenever possible or else be prohibited. The limited grazing allowed in the habitat actually appears to benefit the cactus.

Conservation and Recovery

The objective of the 1990 Uinta Basin Hookless Cactus Recovery Plan (from the FWS), is to delist the species as early as the year 2000. To achieve this goal, the plan calls for inventory of suitable habitat for additional populations, minimum viable population studies on at least six different populations; formal land management designations to provide for long-term, undisturbed habitat, and studies to determine the taxonomic status of morphologically distinct populations.

If these actions are taken, the FWS projects that the species could be delisted, once it can be documented that a total population of 30,000 individuals in six separate populations (of at least 2,000 plants each) exists. Other criteria for delisting include the requirement that these six populations be at minimum viable population levels, and that four of these six populations are preserved and protected on lands with formal management designations to provide long-term, undisturbed habitat.

Contact

U.S. Fish and Wildlife Service
Division of Endangered Species
Denver Federal Center
P.O. Box 25486
Denver, Colorado 80225
http://www.r6.fws.gov/

References

Benson, L. 1982. Cacti of the United States and Canada.Stanford University Press, Stanford.

U.S. Fish and Wildlife Service. 1990. "Uinta Basin Hookless Cactus Recovery Plan." U.S. Fish and Wildlife Service, Denver.