''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.
Description
''Sclerocactus sileri'' grows to about 25 cm tall and 12 cm wide. The cactus also shows a flower of diameter about , with whitish or yellowish petals that show venation in a purple color. Flowering occurs in the spring season.
''Sclerocactus sileri'' has both central and radial spines. Central spines have length up to about and are brownish-black in color. There are four central spines (4-5 per areole),
where the lower central spine is white, abaxial central spines are tinged, is gray-purplish, angled, and strongly hooked and slightly contorted. Central spines are 1.2–3 cm long and 0.5–1 mm wide, curving towards the ground. The two lateral spines are flattened and thicker. The upper central spine is white to tan and is curved and strongly flattened.
Radial spines have length up to about and are white in color. There are about 6-8 radial spines per areole which are acicular.
Seeds are black to light brown in color, and are 2.2-2.5 mm wide, with a rounded papillae.
Flowers and fruits of ''Sclerocactus sileri'' are very similar to others of the same family, such as ''S. whipplei'' or ''S. pubispinus''. The phenology of the flowers from ''Sclerocactus sileri'' bloom during the months of April and May, while the fruits during the months of May and June.
Flowers are 2.5–3 cm (1-1.2 in) long and 2.5–3 cm in diameter, with a glabrous exterior floral tube. The outer tepals have brownish and yellowish margins, the larger oblanceolate, 10–15 mm long, mucronate, marginally membranous and crisped or minutely toothed. The inner tepals are yellow, sometimes suffused with brown, the largest lanceolate, 15–25 mm long and mucronate. The filaments are white or greenish white, 7–10 mm long, anthers yellow, about 1 mm long; style yellowish-green, 14–20 mm long; stigma lobes 5-8 and about 1.2-2.5 mm long; ovary 3–7 mm long at anthesis; scales few, membranous, scarious-margined, minutely toothed or fringed. The fruit is green, turning red, ovoid, dry, and 0.8-2.2 cm long. Fruits extend longitudinally, along two to four ventral slits. Black seeds are 2.75–3 mm in diameter and 2.25- 2.5 mm long.
Taxonomy
The names ''Sclerocactus sileri'' and ''Pediocactus sileri'' have a confused relationship in the literature. (''Sclerocactus'' was included in ''
Pediocactus
''Pediocactus'' (Greek: πεδίον (pedion) means "plain", "flat", "field") is a genus of cacti. The genus comprises between 6 and 11 species, depending upon the authority. Species of this genus are referred to as hedgehog cacti, though that ...
'' by Arp in 1972, but this was not accepted by authorities well conversant in the Cactaceae.)
[, in ] According to the treatment in the ''Flora of North America'',
[, in ] the taxon described here was first named by L.D. Benson (in 1969) as the variety ''sileri'' of ''Sclerocactus pubispinus''. It was raised to a full species under the name ''Sclerocactus sileri'' by K.D. Heil and J.M. Porter in 1994.
Quite separately, ''Echinocactus sileri'' was first described in 1896 and transferred to ''Pediocactus sileri'' by L.D. Benson in 1961.
[, in ] The two taxa are treated as two separate species in the ''Flora of North America'', which has entries for:
* ''Sclerocactus sileri''
(L.D. Benson) K.D. Heil & J M. Porter – Siler fishhook cactus
[
* '']Pediocactus sileri
''Pediocactus sileri'' is a rare species of cactus known by the common names Siler's pincushion cactus and gypsum cactus (or gypsum plains cactus). It is native to southwestern Utah and northwestern Arizona in the United States. It is limited to ...
'' (Engelmann ex J.M. Coulter) L.D. Benson – Gypsum cactus, Siler's pincushion cactus[
Mistakenly, Anderson (2001) describes only one species, under the name ''Sclerocactus sileri'', treating ''Pediocactus sileri'' as a synonym.][, p. 629] His description largely matches the description of ''Pediocactus sileri'' in the ''Flora of North America'', and he uses the same common names (gypsum cactus, Siler's pincushion cactus) although the distribution he gives ("a very restricted area in Coconino County, Arizona") corresponds to that of ''Sclerocactus sileri'' in the ''Flora of North America'' ("restricted to northeast Coconino County, Arizona").[
]
Distribution
''Sclerocactus sileri'' is narrowly distributed. It has been seen in only Arizona,U.S.A, in Coconino County, although it is very close to the Utah border. See Sclerocactus sileri (L. D. Benson) K. D. Heil & J. M. Porter, Haseltonia. 2: 39. 1994.
Habitat and ecology
''Sclerocactus sileri'' is a vascular plant, found in habitats including scrubs, forests, grasslands, and especially desert shrubs. It grows in drier soils that are rich in minerals such as gypsum and salt, and typically in sandy soils derived from Moenkopi Formation. ''Sclerocactus sileri'' grow in grama grass. The following plants are usually associated with the ''Sclerocactus sileri'': drop seed (''Sporobolus
''Sporobolus'' is a nearly cosmopolitan genus of plants in the grass family. The name ''Sporobolus'' means "seed-thrower", and is derived from Ancient Greek word (), meaning "seed", and the root of () "to throw", referring to the dispersion of ...
''), yucca (''Yucca
''Yucca'' is a genus of perennial shrubs and trees in the family Asparagaceae, subfamily Agavoideae. Its 40–50 species are notable for their rosettes of evergreen, tough, sword-shaped leaves and large terminal panicles of white or whitish flo ...
''), hedgehog cactus (''Echinocereus
''Echinocereus'' is a genus of ribbed, usually small to medium-sized, cylindrical shaped cacti, comprising about 70 species native to the southern United States and Mexico in very sunny, rocky places. Usually the flowers are large and the fruit ...
''), sagebrush (''Artemisia
Artemisia may refer to:
People
* Artemisia I of Caria (fl. 480 BC), queen of Halicarnassus under the First Persian Empire, naval commander during the second Persian invasion of Greece
* Artemisia II of Caria (died 350 BC), queen of Caria under th ...
''), snakeweed (''Gutierrezia
''Gutierrezia'' is a genus of flowering plants in the family Asteraceae, native to western North America and western South America. Plants of this genus are known generally as snakeweeds or matchweeds. Some species have been called greasewood. T ...
''), pinyon (''Pinus edulis
''Pinus edulis'', the Colorado pinyon, two-needle piñon, pinyon pine, or simply piñon, is a pine in the pinyon pine group whose ancestor was a member of the Madro-Tertiary Geoflora (a group of drought resistant trees) and is native to the Uni ...
''), and juniper (''Juniperus
Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...
'').
Usage
''Sclerocactus sileri'' has no known uses for humans.
References
* Arizona Game and Fish Department. 2003-04-10. "Sclerocactus sileri". Unpublished abstract compiled and edited by the Heritage Data Management System, Arizona Game and Fish Department, Phoenix, AZ
* Benson, L.D., Heil, K.D., and Porter, J.M, "Sclerocactus sileri". March 2011. Web
* Benson, L.D., Heil, K.D., and Porter, J.M, "Sclerocactus sileri". 20 April 2012. Web
* Benson, L.D., Heil, K.D., and Porter, J.M, "Sclerocactus sileri". Web. 1994
External links
*
USDA Plants Profile for ''Sclerocactus sileri''''Sclerocactus sileri'' — UC Photo gallery
{{Taxonbar, from=Q7434147
Sclerocactus, sileri
Cacti of the United States
Flora of Nevada
Flora of Arizona
Flora of Utah
Natural history of the Mojave Desert