Echinomastus mariposensis (syn.

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 Neolloydia mariposensis, Sclerocactus mariposensis) 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 names Lloyd's fishhook cactus, golfball cactus, silver column cactus, and Mariposa cactus. It is native to a small section of territory straddling the border between Brewster County, Texas

Brewster County, Texas

Brewster County is a county located in western part of the US state of Texas, along the border with Mexico. It is one of the nine counties that comprise the Trans-Pecos region of West Texas. As of the 2000 census, the population is 8,866. In 2009, the population was estimated to be 9,481. Its...

, in the United States and the state of Coahuila

Coahuila

Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...

 in Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

. It has been federally listed as a threatened species in the United States since 1979.

Habitat

This tiny cactus grows at about 30 sites in Texas and Coahuila, many of which are located within Big Bend National Park

Big Bend National Park

Big Bend National Park is a national park located in the U.S. state of Texas. Big Bend has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, which includes more than 1,200 species of plants, more than 450 species of birds, 56...

 and the Black Gap Wildlife Management Area. In Coahuila it has been observed near Cuatro Ciénegas

Cuatro Ciénegas

Cuatro Ciénegas is a city in the northern Mexican state of Coahuila. It stands at , at an average elevation of 740 metres above sea level. The city serves as the municipal seat for the surrounding municipality of the same name....

 and Monclova

Monclova

On the other hand, temperatures during late spring and summer can have bouts of extreme heat, with evenings above 40°C for many consecutive days. In recent decades the hottest records have climbed as high as 43°C on July 13, 2005 and 45°C on May 4, 1984. However nighttime low temperatures are...

. It is named for the Mariposa Mine, a mercury mine

Mercury (element)

Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

 in Texas, where it was first discovered. It was described in 1945. The plant grows in Chihuahuan Desert

Chihuahuan Desert

The Chihuahuan Desert is a desert, and an ecoregion designation, that straddles the U.S.-Mexico border in the central and northern portions of the Mexican Plateau, bordered on the west by the extensive Sierra Madre Occidental range, and overlaying northern portions of the east range, the Sierra...

 scrub amongst other plants such as beaked yucca

Yucca rostrata

Yucca rostrata, also called Beaked yucca, is a tree-like plant belonging to the Yucca genus native to southern U.S. and northern Mexico....

 (Yucca rostrata), creosote (Larrea tridentata), and lechuguilla (Agave lechuguilla), as well as many other cacti. It grows in barren, exposed, rocky habitat with substrates of 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....

; it does not occur in the adjacent parts of the habitat where the rock is 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...

, and the related Echinomastus warnockii fills its niche

Ecological niche

In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...

 there. This cactus may grow alongside the bunched cory cactus

Coryphantha ramillosa

Coryphantha ramillosa is a rare species of cactus known by the common names bunched cory cactus and whiskerbush. It is native to the border region between Texas in the United States and Coahuila in Mexico...

 (Coryphantha ramillosa), another threatened cactus species.

Characteristics

This is a petite cactus growing up to 10 centimeters tall by 6 wide. The body is covered with 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 bearing spines

Thorns, spines, and prickles

In botanical morphology, thorns, spines, and prickles are hard structures with sharp, or at least pointed, ends. In spite of this common feature, they differ in their growth and development on the plant; they are modified versions of different plant organs, stems, stipules, leaf veins, or hairs...

. The central spines are up to 2 centimeters long and are white, gray, or yellow in color with brownish or bluish tips. Each areole also has many radial spines which are smaller and white or gray in color, sometimes with brown tips. The flowers are white, or pink fading to white over time, often with dark midstripes, and up to 3 centimeters long. The fruit is about a centimeter in length and yellow-green in color. Blooming occurs in February and March.

Endangered status

Threats to this rare species have included mercury mining, petroleum exploration activities, 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...

s, and grazing

Grazing

Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...

. The worst threat has been 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...

 by cactus collectors. The collectors employed professional diggers to go into the habitat and retrieve this and other species of cacti, which were stockpiled, shipped away for sale, and sometimes discarded or wasted. The type locality of the cactus has been scoured for specimens and few are found there anymore. Plants in Big Bend National Park occur on rugged terrain and have generally been safe from collectors. In 1983 the cactus was placed on Appendix 1 of CITES in an effort to protect it from harvesting.