Pediocactus despainii is a rare species of cactus known by the common names Despain's pincushion cactus, Despain footcactus, and San Rafael cactus. It is endemic to the state of 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...

 in the United States, where it is limited to the San Rafael Swell

San Rafael Swell

The San Rafael Swell is a large geologic feature located in south-central Utah, USA about 30 miles west of Green River, Utah. The San Rafael Swell, approximately by , consists of a giant dome-shaped anticline of sandstone, shale, and limestone that was pushed up during the Paleocene Laramide...

 in Emery County

Emery County, Utah

Emery County is a county located in the U.S. state of Utah. As of 2000 the population was 10,860, and by 2009 had been estimated to decrease to 10,629. It was named for George W. Emery, governor of the Utah Territory in 1875...

. There are two populations totalling about 6000 individuals. It is threatened by a number of human activities. It is a federally listed endangered species

Endangered species

An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

 of the United States.

This cactus was discovered in 1978 and described to science in 1980. It is sometimes treated as a subspecies or variety of Pediocactus bradyi

Pediocactus bradyi

Pediocactus bradyi is a rare species of cactus known by the common names Brady's pincushion cactus, Brady's hedgehog cactus, and Marble Canyon cactus. It is endemic to Arizona in the United States, where it is known only from Marble Canyon in Coconino County...

. It may occur with its close relative, Pediocactus winkleri

Pediocactus winkleri

Pediocactus winkleri, commonly known as Winkler's cactus or Winkler's pincushion cactus, is a small cactus found only in Emery County, Utah or Wayne County, Utah in eastern Utah....

.

This egg-shaped or somewhat rounded cactus grows up to 6 centimeters tall and about 9 wide, and generally has no branches. It shrinks in size and disappears under the ground in dry and cold times, making it hard to find for most of the year. Each 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...

 bears up to 15 smooth white spines each measuring a few millimeters long. The plant produces a flower up to 2.5 centimeters long and wide with yellowish or pinkish 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 outer ones with purple midstripes. The fruit is green ripening reddish and measures about a centimeter long and wide.

This cactus grows in the San Rafael Swell, a unique geologic feature in central Utah. It is an area with many rare native plants and has a high rate of endemism. The substrate is limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 and siltstone

Siltstone

Siltstone is a sedimentary rock which has a grain size in the silt range, finer than sandstone and coarser than claystones.- Description :As its name implies, it is primarily composed of silt sized particles, defined as grains 1/16 - 1/256 mm or 4 to 8 on the Krumbein phi scale...

 soil originating in the Carmel

Carmel Formation

The Carmel Formation is a geologic formation in the San Rafael Group that is spread across the U.S. states of Wyoming, Utah, Colorado, north east Arizona and New Mexico...

 and Moenkopi Formation

Moenkopi Formation

The Moenkopi is a geological formation that is spread across the U.S. states of New Mexico, northern Arizona, Nevada, southeastern California, eastern Utah and western Colorado. This unit is considered to be a group in Arizona. Part of the Colorado Plateau and Basin and Range, this formation was...

s. The habitat is grassland

Grassland

Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...

 with some juniper

Juniper

Junipers are coniferous plants in the genus Juniperus of the cypress family Cupressaceae. Depending on taxonomic viewpoint, there are between 50-67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the...

s and pinyon pine

Pinyon pine

The pinyon pine group grows in the southwestern United States and in Mexico. The trees yield edible pinyon nuts, which were a staple of the Native Americans, and are still widely eaten...

s. Other flora in the area includes another cactus, Sclerocactus whipplei.

Threats to this species include 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...

, off-road vehicle

Off-road vehicle

An off-road vehicle is considered to be any type of vehicle which is capable of driving on and off paved or gravel surface. It is generally characterized by having large tires with deep, open treads, a flexible suspension, or even caterpillar tracks...

 use, gypsum

Gypsum

Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...

 mining, and petroleum exploration.