Sclerocactus glaucus is a rare species of cactus

Cactus

A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...

 known by the common name Uinta Basin hookless cactus and Colorado hookless cactus. It is endemic to Colorado

Colorado

Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 in the United States, where it is known only from the area between Grand Junction

Grand Junction, Colorado

The City of Grand Junction is the largest city in western Colorado. It is a city with a council–manager government form that is the county seat and the most populous city of Mesa County, Colorado, United States. Grand Junction is situated west-southwest of the Colorado State Capitol in Denver. As...

 and Montrose

Montrose, Colorado

The City of Montrose is a Home Rule Municipality that is the county seat and the most populous city of Montrose County, Colorado, United States. The United States Census Bureau estimates that the city population was 15,479 in 2005. The main road that leads in and out of Montrose is U.S...

. It is a federally listed threatened species.

The description of this species formerly included plants now belonging to Sclerocactus brevispinus

Sclerocactus brevispinus

Sclerocactus brevispinus is a rare species of cactus known by the common name Pariette cactus. It is endemic to Utah in the United States, where it is known only from the Pariette Draw, a draw in Duchesne County. It is threatened by a number of processes and human activities.This plant is federally...

and Sclerocactus wetlandicus

Sclerocactus wetlandicus

Sclerocactus wetlandicus is a rare species of cactus known by the common name Uinta Basin hookless cactus. It is endemic to Utah in the United States, where it is known only from the Uinta Basin. It may also be called the Pariette cactus, but this name is more appropriate for Sclerocactus...

, two cacti endemic to Utah

Utah

Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

. When the second of the two species was separated in 1994, the name S. glaucus was applied only to plants found in Colorado; it made the common name Uinta Basin hookless cactus a misnomer

Misnomer

A misnomer is a term which suggests an interpretation that is known to be untrue. Such incorrect terms sometimes derive their names because of the form, action, or origin of the subject becoming named popularly or widely referenced—long before their true natures were known.- Sources of misnomers...

, because now this species does not occur in the Uinta Basin of Utah. The two new species retained their federally threatened status, which they had received while members of S. glaucus.

This cactus is cylindrical in shape and measures up to 28 centimeters tall by 9 wide, though it is usually much shorter. During the dry season it may shrink so much it disappears beneath the soil surface. There are up to 12 white radial spines on each of its areole

Areole

Areoles are an important diagnostic feature of cacti, and identify them as a family distinct from other succulent plants. The areoles on cacti are clearly visible; they generally appear as small light- to dark-colored bumps, out of which grow clusters of spines...

s, and several straight whitish, reddish, or black central spines pointing in various directions. The central spines may be 1 to 2 centimeters long or more. The fragrant funnel- or bell-shaped flower is up to 5 or 6 centimeters long and has pink tepal

Tepal

Tepals are elements of the perianth, or outer part of a flower, which include the petals or sepals. The term tepal is more often applied specifically when all segments of the perianth are of similar shape and color, or undifferentiated, which is called perigone...

s. The stamen

Stamen

The stamen is the pollen producing reproductive organ of a flower...

s have white or green filaments and yellow anthers. The fruit is barrel

Barrel

A barrel or cask is a hollow cylindrical container, traditionally made of vertical wooden staves and bound by wooden or metal hoops. Traditionally, the barrel was a standard size of measure referring to a set capacity or weight of a given commodity. A small barrel is called a keg.For example, a...

-shaped and up to 2 or 3 centimeters in length.

This plant grows on exposed stretches of gravel

Gravel

Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

ly clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

, including alluvial benches above floodplain

Floodplain

A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...

s and on mesa

Mesa

A mesa or table mountain is an elevated area of land with a flat top and sides that are usually steep cliffs. It takes its name from its characteristic table-top shape....

 slopes. Nearby rivers include the Green

Green River (Utah)

The Green River, located in the western United States, is the chief tributary of the Colorado River. The watershed of the river, known as the Green River Basin, covers parts of Wyoming, Utah, and Colorado. The Green River is long, beginning in the Wind River Mountains of Wyoming and flowing...

, Colorado

Colorado River

The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...

 and Gunnison River

Gunnison River

The Gunnison River is a tributary of the Colorado River, long, in the Southwest state of Colorado. It is the fifth largest tributary of the Colorado River, with a mean flow of 4320 ft³/s .-Description:...

s. It is part of saltbush and sagebrush

Sagebrush

Sagebrush is a common name of a number of shrubby plant species in the genus Artemisia native to western North America;Or, the sagebrush steppe ecoregion, having one or more kinds of sagebrush, bunchgrasses and others;...

-dominated desert shrub plant communities, or pinyon-juniper woodlands. Other plants in the habitat include shadscale

Atriplex confertifolia

Atriplex confertifolia is a species of evergreen shrub in the Chenopodiaceae family, which is native to the western United States.-Habitat:Shadscale is a common, often dominant, shrub in the lowest and driest areas of the Great Basin...

 (Atriplex confertifolia), galleta (Hilaria jamesii), black sagebrush

Artemisia nova

Artemisia nova is a species of sagebrush known by the common name black sagebrush.It is native to the western United States from California to Montana to New Mexico, where it grows in forest, woodland, and grassland habitats. It is "one of the most common shrubs in the western United States"...

 (Artemisia nova), Indian rice grass (Stipa hymenoides), strawberry hedgehog cactus

Echinocereus triglochidiatus

Echinocereus triglochidiatus is a species of hedgehog cactus known by several common names, including Kingcup cactus, Claretcup, and Mojave mound cactus. This cactus is native to the southwestern United States and northern Mexico, where it is a resident of varied habitats from low desert to rocky...

 (Echinocereus triglochidiatus var. melanacanthus), Simpson's pincushion cactus (Pediocactus simpsonii), prickly pear cactus

Opuntia polyacantha

Opuntia polyacantha is a common species of cactus known by the common names plains pricklypear, hairspine cactus, panhandle pricklypear, and starvation pricklypear. It is native to North America, where it is widespread in western Canada, the central and western United States, and northern...

 (Opuntia polyacantha), winterfat

Krascheninnikovia lanata

Krascheninnikovia lanata is a species of flowering plant in the amaranth family known by the common name Winterfat. It is native to much of western North America: from central Western Canada; through the Western United States; to Northern Mexico...

 (Krascheninnikovia lanata), yucca (Yucca harrimaniae), snakeweed

Gutierrezia sarothrae

Gutierrezia sarothrae is a species of flowering plant in the daisy family known by the common names broom snakeweed and perennial matchweed. It is native to much of the western half of North America, from central Canada to northern Mexico...

 (Gutierrezia sarothrae), low rabbitbrush

Chrysothamnus viscidiflorus

Chrysothamnus viscidiflorus is a species of shrub in the daisy family known by the common names yellow rabbitbrush and green rabbitbrush. It is native to western North America, from British Columbia to California to Nebraska, where it grows in sagebrush and woodland habitat. It grows easily in...

 (Chrysothamnus viscidiflorus), sand dropseed

Sporobolus cryptandrus

Sporobolus cryptandrus is a species of grass known by the common name sand dropseed. It is native to North America, where it is widespread throughout southern Canada, most all of the United States, and northern Mexico.-Habitat:...

 (Sporobolus cryptandrus), and Salina wildrye (Elymus salinus).

This cactus faces a number of threats. Almost all of the populations are threatened by habitat loss and degradation due to human activities such as hydrocarbon exploration, residential development, rock mining, and the introduction of livestock

Livestock

Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

 to the area. It has been affected by the TransColorado Pipeline

TransColorado Pipeline

TransColorado Pipeline is a natural gas pipeline that transports gas across Colorado to either the San Juan Basin or Denver and the Colorado Interstate Gas system. It is owned by Kinder Morgan Energy Partners. Its FERC code is 143.-External links:*...

. The petroleum industry is expected to attract a large population to this rural area. Poaching

Poaching

Poaching is the illegal taking of wild plants or animals contrary to local and international conservation and wildlife management laws. Violations of hunting laws and regulations are normally punishable by law and, collectively, such violations are known as poaching.It may be illegal and in...

is also a problem.