Sclerocactus

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Ordo: Caryophyllales

Familia: Cactaceae
Subfamilia: Cactoideae
Tribus: Cacteae
Genus: Sclerocactus
Sectiones: S. sect. Coloradoa – S. sect. Parviflori – S. sect. Sclerocactus – insertae sedis
Species: S. blainei – S. brevihamatus – S. brevispinus – S. cloverae – S. glaucus – S. intertextus – S. johnsonii – S. mariposensis – S. mesae-verdae – S. nyensis – S. papyracanthus – S. parviflorus – S. polyancistrus – S. pubispinus – S. scheeri – S. sileri – S. spinosior – S. unguispinus – S. warnockii – S. wetlandicus – S. whipplei – S. wrightiae –
Source(s) of checklist:

Govaerts, R. et al. 2021. Sclerocactus in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the internet. Accessed: 2021 Mar 26. Reference page.

Name

Sclerocactus Britton & Rose, Cactaceae 3: 212. 1922.

Type species: Sclerocactus polyancistrus (Engelm. & Bigelow) Britton & Rose

Synonyms

Homotypic
Echinocactus subg. Sclerocactus (Britton & Rose) A.Berger, Kakteen 8: 249. 1929.
Ferocactus sect. Sclerocactus (Britton & Rose) N.P.Taylor, Cact. Succ. J. Gr. Brit. 41(4): 90. 1979.
Pediocactus sect. Sclerocactus (Britton & Rose) Halda, Acta Mus. Richnov., Sect. Nat. 5(1): 14. 1998.

Heterotypic
Ancistrocactus Britton & Rose, Cactaceae 4: 4, fig. 1. 1923.
Ferocactus subg. Ancistrocactus (Britton & Rose) N.P.Taylor, Cact. Succ. J. Gr. Brit. 41(4): 90. 1979.
Type species: Ancistrocactus megarhizus Britton & Rose
Coloradoa Boissev. & C.Davidson, Colorado Cact. 54. 1940.
Type species: Coloradoa mesae-verdae Boissev. & C.Davidson
Echinocactus [infragen. unranked] Megarhizi Vaupel in Engl. (ed.), Nat. Pflanzenfam. 21: 623, 628. 1925.
Type species: Echinocactus megarhizus Rose
Echinocactus [infragen. unranked] Polyancistri Vaupel in Engl. (ed.), Nat. Pflanzenfam. 21: 623, 628. 1925.
Type species: Echinocactus polyancistrus Engelm.
Echinocactus ser. Gymnanthi A.Berger, Kakteen: 8: 249. 1929, p.p.
Type species: non design.
Echinocactus ser. Hamati Salm-Dyck, Cact. Hort. Dyck. 1849: 28, 151, 152. 1850, p.p.
Type species: non design.
Echinocactus ser. Lepidanthi A.Berger, Kakteen: 7: 235. 1929, p.p.
Type species: non design.
Echinocactus subg. Ancistrocactus K.Schum., Gesamtbeschr. Kakt., 292, 334. 1898.
Type species: Echinocactus uncinatus Galeotti
Glandulicactus Backeb., Blätt. Kakteenf. 1938(6): [18; 10, 13, 25]. 1938.
Hamatocactus subg. Glandulicactus (Backeb.)
Type species: Glandulicactus uncinatus (Galeotti ex Pfeiff.) Backeb. Buxb. in Krainz, Die Kakteen (25) CVIIIb: [4-5]. (1 Nov) 1963, nom. illeg.
Mammillaria [infragen. unranked] Albiflorae Engelm., Syn. Cact. U. S. 8. 1856, nom. inval.
Type species: Mammillaria papyracantha Engelm.
Roseia Frič, Zivot v Prirode 29(1): 15 (fig), & 29(7): 9. 1925, nom. illeg. non Rosea Mart. (1826).
Type species: Roseia castanedae Frič
Toumeya Britton & Rose, Britton & Rose, Cactaceae (Britton & Rose) 3: 91. 1922, nom. illeg. non Tuomeya Harv. (1858).
Pediocactus subg. Toumeya (Britton & Rose) Halda, Acta Mus. Richnov., Sect. Nat. 5(1): 17. 1998.
Type species: Toumeya papyracantha (Engelm.) Britton & Rose

Distribution
Native distribution areas:

Continental: Northern America
Arizona, California, Colorado, Mexico Northeast, Mexico Northwest, Nevada, New Mexico, Texas, Utah

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References
Primary references

Britton, N.L. & Rose, J.N. 1922. The Cactaceae. Descriptions and Illustrations of Plants of the Cactus Family. Vol. 3. 255 pp. + 23 pl. Carnegie Institution of Washington. BHL PDF Reference page. : 3: 212.
Doweld, A.B. 2001. The genus Ancistrocactus Britton & Rose. Phylogenetic relationships and classification [Il genere Ancistrocactus Britton & Rose. Relazione filogenetiche e classificazione]. Cactus & Co. 5(2): 62–102. Reference page.
Doweld, A.B. & Greuter, W. 2001. Nomenclatural notes on Ancistrocactus (Cactaceae). Taxon 50(3): 875–878. DOI: 10.2307/1223716 Reference page.

Links

Govaerts, R. et al. 2021. Sclerocactus in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the internet. Accessed: 2021 Mar 26. Reference page.
International Plant Names Index. 2021. Sclerocactus. Published online. Accessed: Mar 26 2021.
Tropicos.org 2021. Sclerocactus. Missouri Botanical Garden. Published on the internet. Accessed: 2021 Mar 26.
Hassler, M. 2021. Sclerocactus. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2021. Species 2000 & ITIS Catalogue of Life. Published on the internet. Accessed: 2021 Mar 26. Reference page.
'eFloras (2008) Ancistrocactus in Flora of North America. Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
eFloras 2008. Sclerocactus in Flora of North America . Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
USDA, ARS, Germplasm Resources Information Network. Sclerocactus in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 09-Oct-10.

Vernacular names
English: Fishhook Cactus
suomi: Kynsikaktukset
lietuvių: Standenis
svenska: Sklerokaktussläktet

Sclerocactus ("hard cactus", from Greek; refers to the hard, dry fruit) 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.'

Description

Sclerocactus are ovoid to elongate cylindric, have rigid stems with tubercles that are generally coalesced into ribs, and are covered with spines that come out of the areoles.[1] 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, or in the Mohave Desert or the Great Basin. They are well suited to extremes due to lack of rainfall, hot summers and below freezing winters.
S. parviflorus growing on its side with wood debris nearby

The little barrel cactus typically grows in areas where water flows irregularly or depressions where water can accumulate for short periods of time. They are most often found growing along washes and arroyos where their seeds have been subjected to scarification 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 sometimes hooked or curved 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 borne 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.

Synonymy

Sclerocactus was once reduced to synonymy with Pediocactus—but this is not accepted; these genera are not closely related.[1] The following genera have been brought into synonymy with Sclerocactus and this is commonly accepted:

Coloradoa Boissev. & C.Davidson
Toumeya Britton & Rose

The following have been proposed for synonymy with Sclerocactus but this is controversial. They are closely related, as shown by molecular genetic and other research:[1][2]

Ancistrocactus Britton & Rose
Echinomastus Britton & Rose
Glandulicactus Backeb.
Homalocephala Britton & Rose

Species

The relationship between Sclerocactus and other genera, including Ancistrocactus, is unclear as of May 2012.[3] As a result, the number of species included in the genus varies: the Flora of North America (FNA) recognizes 15 species,[1] Anderson recognizes 14. Anderson's list is given below,[4] with the treatment in the FNA shown in parentheses.

Sclerocactus brevihamatus (FNA treats this as Ancistrocactus brevihamatus[5])
Sclerocactus glaucus (FNA separates out S. brevispinus and S. wetlandicus)
Sclerocactus mesae-verdae
Sclerocactus nyensis
Sclerocactus papyracanthus
Sclerocactus parviflorus (FNA separates out S. cloverae)
Sclerocactus polyancistrus
Sclerocactus pubispinus
Sclerocactus scheeri
Sclerocactus sileri
Sclerocactus spinosior (FNA separates out S. blainei)
Sclerocactus uncinatus
Sclerocactus whipplei
Sclerocactus wrightiae

Many species of Sclerocactus are protected under the provisions of the Endangered Species Act and all species should be treated as imperiled.
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 accumulate for short period of time. They are most often found growing along washes and arroyos where their seeds have been subjected to scarification 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 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, 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 to bloom well.

Some species, such as S. parviflorus, produce large, showy flowers and put 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. 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.
References

Heil, Kenneth D. & Porter, J. Mark, Sclerocactus, retrieved 2012-05-04, in Flora of North America Editorial Committee, ed. (1982), Flora of North America (online), eFloras.org
Heil, Kenneth D. & Porter, J. Mark (1994), "Sclerocactus (Cactaceae): a revision", Haseltonia, 2: 20–46
Anderson, Edward F. (2001), The Cactus Family, Pentland, Oregon: Timber Press, ISBN 978-0-88192-498-5, pp. 557, 625
Anderson 2001, pp. 625–629.
Zimmerman, Allan D. & Parfitt, Bruce D., Ancistrocactus brevihamatus, retrieved 2012-05-04, in Flora of North America Editorial Committee, ed. (1982), Flora of North America (online), eFloras.org