Origin and Habitat: Coryphantha clavaSN|3914]]SN|3896]] (= Coryphantha octacanthaSN|3893]]SN|3893]]) is endemic to Mexico. It has been reported to be present in the states of Aguascalientes, Guanajauto, Hidalgo, and Querétaro, also it rarely occurs in the states of San Luis Potosí and in Tamaulipas. This is a widespread species found at innumerable localities, with a very large population, and with many plants occurring in huge groups in remote areas.
Habitat and Ecology: The species grows in dry grassland on limestone gravel or alluvial soils at the foot of hills and on ridges. Accompanying species can be Echeveria secundaSN|27133]]SN|27133]], Dasylirion acrotichum, Echinocereus cinerascensSN|7775]]SN|7775]], Ferocactus latispinusSN|4259]]SN|4259]], Myrtillocactus geometrizansSN|8050]]SN|8050]], Stenocereus dumortieriSN|7942]]SN|7942]], Opuntia imbricataSN|8157]]SN|8157]], Coryphantha radiansSN|3896]]SN|3914]], Gymnocactus horripilusSN|12124]]SN|12124]], Mammillaria geminispinaSN|14012]]SN|14012]], Echinocactus platyacanthus, and Neolloydia conoideaSN|10089]]SN|10089]]. Although there is some illegal collection, this does not appear to be a major threat. The main threat to the species is increasing frequency of fires to renew grazing areas for livestock.

• Coryphantha clava (Pfeiff.) Lem.
• Aulacothele clava (Pfeiff.) Monv.
• Cactus clavus (Pfeiff.) Kuntze
• Glandulifera clava (Pfeiff.) Frič
• Mammillaria clava Pfeiff.

• Coryphantha octacantha (DC.) Britton & Rose
• Cactus octacanthus (DC.) Kuntze
• Mammillaria octacantha DC.
• Coryphantha aulacothele Lem.
• Cactus aulacothele Kuntze
• Mammillaria aulacothele Lem.
• Coryphantha aulacothele var. flavispina (Salm-Dyck)
• Mammillaria aulacothele var. flavispina Salm-Dyck
• Coryphantha aulacothele var. multispina (Scheidw.)
• Mammillaria aulacothele var. multispina Scheidw.
• Coryphantha aulacothele var. spinosior (Monv. ex Lem.)
• Mammillaria aulacothele var. spinosior Monv. ex Lem.
• Coryphantha biglandulosa (Pfeiff.)
• Aulacothele biglandulosa (Pfeiff.) Monv.
• Cactus biglandulosus (Pfeiff.) Kuntze
• Glandulifera macrothele var. biglandulosa (Pfeiff.) Frič
• Mammillaria biglandulosa Pfeiff.
• Mammillaria macrothele var. biglandulosa (Pfeiff.) Salm-Dyck
• Coryphantha brevimamma (Zucc.) Lem. ex Rümpler
• Cactus brevimammus (Zucc.) Kuntze
• Coryphantha clava (Pfeiff.) Lem.
• Aulacothele clava (Pfeiff.) Monv.
• Cactus clavus (Pfeiff.) Kuntze
• Glandulifera clava (Pfeiff.) Frič
• Mammillaria clava Pfeiff.
• Coryphantha lehmannii Lem.
• Aulacothele lehmannii (Otto) Monv.
• Cactus lehmannii (Otto ex Pfeiff.) Kuntze
• Mammillaria lehmannii Link & Otto ex Pfeiff.
• Mammillaria macrothele var. lehmannii (Otto ex Pfeiff.) Salm-Dyck
• Coryphantha macrothele (Mart. ex Pfeiff.) Kümmler
• Mammillaria macrothele Mart. ex Pfeiff.
• Coryphantha plaschnickii (Otto ex Pfeiff.)
• Aulacothele plaschnickii (Otto) Monv.
• Echinocactus plaschnickii (Otto) Poselg.
• Mammillaria plaschnickii Otto ex Pfeiff.
• Coryphantha plaschnickii var. straminea (Salm-Dyck)
• Mammillaria plaschnickii straminea Salm-Dyck
• Coryphantha schlechtendalii (Ehrenb.) Lem.
• Aulacothele schlechtendahlii (Ehrenb.) Monv.
• Aulacothele schlechtendalii (Ehrenb.) Monv.
• Cactus schlechtendalii (Ehrenb.) Kuntze
• Coryphantha clava var. schlechtendalii (Ehrenb.) Heinrich ex Backeb.
• Echinocactus schlechtendalii (Ehrenb.) Poselg.
• Mammillaria schlechtendalii Ehrenb.
• Coryphantha sulcimamma (Pfeiff. ex Salm-Dyck)
• Aulacothele sulcimamma (Pfeiff.) Monv.
• Mammillaria aulacothele var. sulcimamma (Pfeiff.) Walp. in Walp.
• Mammillaria sulcimamma Pfeiff. ex Salm-Dyck

Description: Coryphantha clavaSN|3896]]SN|3896]] continues to exist in the whole cactus literature until today, although its description does not show any differences to the ones of the complex around Coryphantha octacanthaSN|3896]]SN|3893]], and should be fully synonymized with the latter. Coryphantha clavaSN|3893]]SN|3896]], with a club-shaped, deep green body and white and yellow spines, grows prolifically. Plants are solitary or branch basally to form clumps. The axils of the tubercles are filled with white wool, with a vivid scarlet gland at the base of the groove. The pale-yellow blossoms are very large and showy, the outer segments tinged with scarlet. This striking species is widely cultivated as an ornamental. Given the wide range of this species and its appearance, it was collected and sent to Europe very early.
Derivation of specific name: “clava', club; for the shape of the stem segments.
Stem: Cylindrical to club-shaped, deep green, up to 30 cm tall, initially erect but becoming prostrate with age.
Tubercles: Erect, elongated, somewhat 4-sided Axils of tubercles with white wool and with a red gland at base of groove. The glands tend to exude a sugary solution when growing.
Areoles: Coryphantha clavaSN|3896]]SN|3896]] has a common type of spine-areole, white-villous with a strong central spine that is somewhat curved and numerous thin radial spines that tend to lie flat against the stem.
Radial spines: Usually 7, straight, horn-colored, about equal.
Central spine: A little longer and stouter than the others.
Flowers: Very large, sometimes 9 cm broad, pale yellow, with the outer segments tinged
with red; perianth-segments glossy, linear-oblong to spatulate, outer ones entire, inner ones serrate
and mucronate at apex; filaments orange; stigma-lobes 6, linear, yellow.

Bibliography: Major references and further lectures
1) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
2) James Cullen, Sabina G. Knees, H. Suzanne Cubey "The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass" Cambridge University Press, 11/Aug/2011
3) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
4) N. L. Britton, J. N. Rose “The Cactaceae. Descriptions and Illustrations of Plants of the Cactus Family.” Volume 4, The Carnegie Institution of Washington, Washington 1923
5) Curt Backeberg “Die Cactaceae: Handbuch der Kakteenkunde” Gustav Fischer Verlag, Stuttgart New York 1982–1985
6) Reto Dicht, Adrian Lüthy “Coryphantha: Cacti of Mexico and Southern USA” Springer Science & Business Media, 14 March 2006
7) Arthur C. Gibson, Park S. Nobel “The Cactus Primer” Harvard University Press, 1990
8) Cecile Hulse Matschat “Mexican Plants for American Gardens” Houghton Mifflin, 1935
9) Sánchez , E., Guadalupe Martínez, J., Lüthy, A.D. & Dicht, R.F. 2013. Coryphantha octacantha. The IUCN Red List of Threatened Species. Version 2015.1. <www.iucnredlist.org>. Downloaded on 08 June 2015.
10) Terry Hewitt “Cacti” Lorenz Books, 1998
11) Urs Eggli, Leonard E. Newton “Etymological Dictionary of Succulent Plant Names” Springer Science & Business Media, 29 June 2013

Cultivation and Propagation: Coryphantha clavaSN|3896]]SN|3896]] is popular with collectors and easy to grow. It comes from an area of summer rainfall. Keep drier in winter (but for outdoor cultivation it is quite resistant to wet conditions, too). Quite cold resistant, hardy about to about -10° C, but the frost resistance varies a lot from clone to clone. Needs good drainage. Keep drier in winter, Full sun to partial shade.
Propagation: Seeds (no dormancy requirement, they germinate best at 25°C) or by offsets (if available), or occasionally grafted.