| Pediocactus knowltonii | |
|---|---|
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Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Cactaceae |
| Subfamily: | Cactoideae |
| Genus: | Pediocactus |
| Species: | P. knowltonii |
| Binomial name | |
| Pediocactus knowltonii | |
| Synonyms | |
| |
Pediocactus knowltonii is a rare species of cactus known by the common names Knowlton's miniature cactus, Knowlton's pincushion cactus, and Knowlton's minute cactus.
A tiny cactus, it may reach a maximum size of 55 millimeters tall by 30 mm wide. It is often smaller, growing to the size of a US penny. [3] An individual is considered to be an adult when it exceeds 10 mm in diameter. [4] It is spherical or somewhat cylindrical in shape. The areoles are round and covered in hairs. Each areole has up to 26 radial spines which are red, pink, or white in color. The spines are less than 2 mm long. The plant produces a flower up to 35 mm long by 25 mm wide with pinkish tepals, the outer ones sporting brownish midstripes. The fruit is green, ripening reddish, and measures about 4 mm long. According to a genetic analysis, this species probably evolved as a mutation of the larger Pediocactus simpsonii . [5]
It is endemic to San Juan County, New Mexico in the United States, [4] where there is a single population on a patch of territory measuring about 12 acres (49,000 m2). [6] As of 2008, there are approximately 6100 individuals in this population. The cactus occurs on land very close to the Colorado border; in fact, it has been observed within 30 meters (100 ft) of the state border, but it does not technically occur within the state of Colorado, and is thus an endemic of New Mexico. [4] Its habitat is pinyon-juniper woodland and sagebrush with loamy, gravelly alluvial soils. [3] In some areas the substrate is covered in cobbles. [4] The cactus may grow in the open or in the shade of larger plants. [6]
It is the smallest and rarest species in the genus Pediocactus . [5] It is threatened by a number of human activities, and is considered Critically Imperiled by NatureServe. [6] It is federally listed as an endangered species of the United States. The population is partly fenced and protected by The Nature Conservancy. [4]
The plant was discovered in 1958. [4] It was immediately sought by collectors of cacti and within 20 years the population had been severely reduced. There may have been 100,000 individuals around the time it was discovered, and this number had been reduced to about 1000 by 1978. [4] It is still a desirable specimen for cactus collectors because of its tiny size and rarity. [6] The seed is available via the internet for about $10 per 100 seeds. [4]
Other threats include off-road vehicle use and development near the population, as well as petroleum exploration activities (which are common in the area), livestock grazing, and drought. Additionally, rodents (especially deer mice) eagerly consume the fruits, causing seed production to be low. [4]
Bergerocactus emoryi is a species of cactus, known commonly as the golden-spined cereus, golden snake cactus, velvet cactus or golden club cactus. It is a relatively small cactus, but it can form dense thickets or colonies, with the dense yellow spines giving off a velvety appearance when backlit by the sun. From April to May, yellow, green-tinged flowers emerge, which transform into reddish, globular fruit. This species is native to the California Floristic Province, and is found in northwestern Baja California and a small part of California, in San Diego County and on the southern Channel Islands. Where the Mediterranean climate of the California Floristic Province collides with the subtropical Sonoran Desert near El Rosario, hybrids with two other species of cacti are found. It is the sole member of the monotypic genus Bergerocactus, named after German botanist Alwin Berger.
Sclerocactus is a genus of cacti. It comprises about 15 species, the exact number depending on the authority. These species are very xerophytic. They are sometimes called 'fishhook cactus' or 'little barrels.'
Morangaya is a monotypic genus of ribbed, usually small to medium-sized, cylindrical shaped cacti, that is native to north western Mexico. The only species is Morangaya pensilis. It is found in the mountains and rocky hills.
Yavia cryptocarpa is a species of cactus and the only species of the newly discovered genus Yavia. The genus is named after Argentina's department Yavi, Jujuy Province, where the plant is endemic to sparsely vegetated rocky slopes. The plant is also sometimes put in the tribe Notocacteae. The specific epithet cryptocarpa refers to the plant being a cryptocarp. This means that the fruits are formed inside the plant's body, thus being only visible when the plant shrinks in the drought period.
Pediocactus bradyi subsp. winkleri, commonly known as Winkler's cactus or Winkler's pincushion cactus, is a small cactus endemic to the state of Utah in the United States. It is known only from Emery and Wayne Counties.
Ariocarpus agavoides is a species of cactus. It is endemic to Mexico. It grows in dry shrubland in rocky calcareous substrates. Some taxonomists place it in a separate genus as Neogomezia agavoides. The locals use the slime from the roots of the plants as glue to repair pottery. The sweet-tasting warts are eaten and often added to salads
Opuntia basilaris, the beavertail cactus or beavertail pricklypear, is a cactus species found in the southwest United States. It occurs mostly in the Mojave, Anza-Borrego, and Colorado Deserts, as well as in the Colorado Plateau and northwest Mexico. It is also found throughout the Grand Canyon and Colorado River region as well as into southern Utah and Nevada, and in the western Arizona regions along the Lower Colorado River Valley.
Aztekium ritteri is a species of cactus native to the Mexican state of Nuevo León.
Escobaria robbinsorum is a rare species of cactus known by the common names Cochise pincushion cactus and Cochise foxtail cactus. It is native to southern Arizona in the United States, where it is known only from Cochise County, and northern Sonora in Mexico. There are scattered small occurrences on the north side of the border, and one known population to the south. Because of its rarity and a number of threats to remaining plants, the species was federally listed with a threatened status in 1986.
Echinocereus fendleri is a species of cactus known by the common names pinkflower hedgehog cactus and Fendler's hedgehog cactus. It is named in honor of Augustus Fendler.
Pediocactus sileri is a rare species of cactus known by the common names Siler's pincushion cactus and gypsum cactus. It is native to southwestern Utah and northwestern Arizona in the United States. It is limited to a specific type of soil, individuals are often spaced far apart, and the species is threatened by a number of human activities such as off-road vehicle use, poaching, and uranium mining. This is a federally listed threatened species of the United States.
Pediocactus bradyi is a very 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 US, where it is restricted to Marble Canyon in Coconino County, though its exact distribution is not generally advertised due to poaching concerns. It is limited to a specific type of soil, it has a small distribution, and the species is threatened by a number of human activities. This has been a federally listed endangered species of the United States since 1979.
Pediocactus despainii is a rare species of cactus known by the common names Despain's cactus and San Rafael cactus.
Pediocactus peeblesianus is a rare species of cactus known by the common names Navajo pincushion cactus. It is endemic to the state of Arizona in the United States. The species is named after the Arizona botanist Robert Hibbs Peebles.
Sclerocactus glaucus is a rare species of cactus known by the common name Colorado hookless cactus. It is endemic to Colorado in the United States, where it is known only from the area between Grand Junction and Montrose. It is a federally listed threatened species.
Sclerocactus sileri, the Siler fishhook cactus, is a rare and very small cactus found mostly in mineral-rich desert areas of intermediate elevations, notably in the American states of Utah, Nevada, and northern Arizona.
Cereus jamacaru, known as mandacaru or cardeiro, is a cactus native to central and eastern Brazil. It often grows up to 6 metres high.
Sclerocactus mesae-verdae, the Mesa Verde cactus or Mesa Verde fishhook cactus, is a species of cactus native to northwestern New Mexico and southwestern Colorado. It is known only from Montezuma County (Colorado) and San Juan County. Much of the New Mexico part of the range lies inside land controlled by the Navajo Nation. The Colorado populations lie close to Mesa Verde National Park.
Pediocactus simpsonii, known by the common names mountain cactus, snowball cactus, and mountain ball cactus is a species of Cactus. It the most commonly found species in the small Pediocactus genus and is noted as being one of the most cold hardy of the cactuses and grows at a higher elevation than any other North American species of cactus. It is somewhat often grown in gardens, and collection of plants from the wild threatens this species in some areas.
Pediocactus paradinei, also known as bristly plains cactus, Houserock Valley cactus, Kaibab pincushion cactus, Paradine cactus, and Park pincushion cactus is a rare species of cactus found in Arizona.
Media related to Pediocactus knowltonii at Wikimedia Commons