Sclerocactus
Encyclopedia
Sclerocactus is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of cacti
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...

. 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'.

Description

Sclerocactus are ovoid to elongate cylindric, have rigid stems with tubercle
Tubercle
A tubercle is generally a wart-like projection, but it has slightly different meaning depending on which family of plants or animals it is used to refer to....

s that are generally coalesced into ribs, and are covered with spines that come out of the 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. Most species have at least one hooked spine at each areole. Less often, species may not have hooks.

These plants are found in higher elevation deserts such as on the Colorado Plateau
Colorado Plateau
The Colorado Plateau, also called the Colorado Plateau Province, is a physiographic region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. The province covers an area of 337,000 km2 within western Colorado, northwestern New Mexico,...

, or in the Mohave Desert or the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...

. They are well suited to extremes due to lack of rainfall, hot summers and below freezing winters.
The fishhook cactus typically grows in areas where water flows irregularly or depressions where water can accmulate for short periods of time. They are most often found growing along washes and arroyos where their seeds have been subjected to scarfication due to water movement, but they oddly also tend to grow along ridges in spots where depressions have formed and can hold water for some period of time.

The "fishhook" spines and the armored web of spines enclosing the cactus body in species of this genus is an adaptation which allows the plant to move to more favorable locations. This plants seeds germinate in areas where water movement occurs or in areas where standing water accumulates for some period of time, and during flash floods, the hooked spines allow the plants to be caught on water bourne debris and be uprooted and carried to areas where water tends to accumulate. A large percentage of plants in habitat show signs of water debris damage along the stems which has healed and are found growing on their sides in places where floodwaters have deposited them. The habitat these plants exist in is very arid, and the plants have adapted to exploit water movement to concentrate their biomass in areas where water is likely to be present.

Species

  • Many species of Sclerocactus are protected under the provisions of the Endangered Species Act
    Endangered Species Act
    The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...

     and all species should be treated as imperiled.

  • Sclerocactus parviflorus is the most common species; its flowers are usually pink, but are yellow in a few areas (see photo) or, rarely, white or intermediate shades.

These two species were first collected by Andrew Lafayette (A.L.) Siler in Southern Utah/Northern Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

, who lived in Kanab, 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...

, at the time:
  • Sclerocactus polyancistrus
    Sclerocactus polyancistrus
    Sclerocactus polyancistrus is a species of cactus known by several common names, including Mojave fishhook cactus, pineapple cactus and hermit cactus.-Distribution:...

    is the ‘giant’ of the genus
    Genus
    In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

    . Some species are quite rare and need considerable further study.
  • Sclerocactus sileri is sometimes confused in nomenclature with Pediocactus sileri, because of the same specific epithet.

Synonymy

  • Sclerocactus was once reduced to synonymy
    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...

     with Pediocactus
    Pediocactus
    Pediocactus is a genus of cacti. The genus comprises between 6 and 11 species, depending upon the authority...

    —but this is not accepted; these genera are not closely related.


The following genera have been brought into synonymy with Sclerocactus and this is commonly accepted:
  • Coloradoa Boissev. & C.Davidson
  • Toumeya Britton
    Nathaniel Lord Britton
    Nathaniel Lord Britton was an American botanist and taxonomist who founded the New York Botanical Garden in the Bronx, New York. Britton was born in New Dorp in Staten Island, New York...

     & Rose
    Joseph Nelson Rose
    Joseph Nelson Rose was an American botanist. He was born in Union County, Indiana. His father died serving during the Civil War when Joseph Rose was a young boy. He later graduated from high school in Liberty, Indiana....



The following have been proposed for synonomy with Sclerocactus but this is controversial. They are closely related, as shown by molecular genetic and other research:
  • Ancistrocactus Britton
    Nathaniel Lord Britton
    Nathaniel Lord Britton was an American botanist and taxonomist who founded the New York Botanical Garden in the Bronx, New York. Britton was born in New Dorp in Staten Island, New York...

     & Rose
    Joseph Nelson Rose
    Joseph Nelson Rose was an American botanist. He was born in Union County, Indiana. His father died serving during the Civil War when Joseph Rose was a young boy. He later graduated from high school in Liberty, Indiana....

  • Echinomastus Britton
    Britton
    -Places:* Britton, Ontario, Canada* Britton, Michigan, U.S.* Britton, South Dakota, U.S.-Surname:* Andrew Britton , British-born American author* Brent Britton , American lawyer...

     & Rose
    Rose
    A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. Flowers are large and showy, in colours ranging from white through yellows...

  • Glandulicactus Backeb.
  • Homalocephala Britton
    Britton
    -Places:* Britton, Ontario, Canada* Britton, Michigan, U.S.* Britton, South Dakota, U.S.-Surname:* Andrew Britton , British-born American author* Brent Britton , American lawyer...

     & Rose
    Rose
    A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. Flowers are large and showy, in colours ranging from white through yellows...




Cultivation and Propagation

Sclerocactus are easy to cultivate. They are generally a cold-adapted genus. They grow in very arid areas which are subjected to deep cold in spots where water flows irregularly or depressions where water can accmulate for short period of time. They are most often found growing along washes and arroyos
Arroyo (creek)
An arroyo , a Spanish word translated as brook, and also called a wash is usually a dry creek or stream bed—gulch that temporarily or seasonally fills and flows after sufficient rain. Wadi is a similar term in Africa. In Spain, a rambla has a similar meaning to arroyo.-Types and processes:Arroyos...

 where their seeds have been subjected to scarification
Scarification
Scarifying involves scratching, etching, burning, or superficially cutting designs, pictures, or words into the skin as a permanent body modification.In the process of body scarification, scars are formed by cutting or branding the skin...

 due to water movement, but they oddly also tend to grow along ridges in spots where depressions have formed and can hold water for some period of time.

They undergo most of their growth in spring and benefit from moderate fertilizer
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...

 in cultivation. They prefer mineral-rich, sandy soils. They are tolerant of overwatering provided they are grown in small pots that drain and dry out quickly. They do best out of doors do well in full sun. They are not particularly attractive plants and their vicious hooked spines are a hazard, making them poor houseplants. Like Pediocactus
Pediocactus
Pediocactus is a genus of cacti. The genus comprises between 6 and 11 species, depending upon the authority...

, Sclerocactus "deflate" in late fall in preparation for winter and freezing; they push water out of the plant flesh, through the roots, and into the soil, dramatically decreasing in size. They require deep cold and dormancy
Dormancy
Dormancy is a period in an organism's life cycle when growth, development, and physical activity are temporarily stopped. This minimizes metabolic activity and therefore helps an organism to conserve energy. Dormancy tends to be closely associated with environmental conditions...

 to bloom well.

Some species, such as S. parviflorus, produce large, showy flowers and put an a short, but impressive floral display in early spring.

Sclerocactus seeds are difficult to germinate as they contain inhibitors, and require cold stratification, prolonged soaking, or scarification of the seeds to trigger germination
Germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...

. Seeds of members of this genus can take up to three years to germinate in some cases if not scarified or subjected to repeated freeze-thaw cycles in the presence of water. The plants are easy to maintain in cultivation but difficult to start from seed.

External links

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