Origin and Habitat: 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. 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 octacantha (DC.) Britton & Rose
• Cactus octacanthus (DC.) Kuntze
• Mammillaria octacantha DC.

• 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 octacanthaSN|3893]]SN|3893]] with olive green body and white and yellow spines, grows prolifically. Plants are solitary or branch basally to form clumps up to 30 or more cm tall. The axils of the tubercles are filled with white wool, with vivid scarlet glands at the base of the groove. The canary-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, it is quite variable and has received numerous names of controversial botanical value.
Stem: Oblong to short cylindrical, solitary or branching basally, deep green to olive green, up to 30 cm tall, and 10(-15) cm in diameter, initially erect but becoming prostrate with age.
Tubercles: Loosely arranged, conical, erect, elongated, somewhat 4-sided broad bases, to 25-30 mm long. Axils of tubercles with white wool and with one or two red gland at base of groove. The glands tend to exude a sugary solution when growing. A peculiarity of Coryphantha octacanthaSN|3893]]SN|3893]] is that it may have grooved and grooveless tubercles on the same mature heads at the same time, or may change the form of its growth back and forth from the one to the other.
Areoles: This species has a common type of spine-areole, white-villous with strong central spines that are somewhat curved and numerous thin radial spines that tend to lie flat against the stem.
Radial spines: Usually 7-8, awl shaped, thin, rigid, straight, about equal, yellowish with dark tips or horn-colored with black tips, 10-15 mm long.
Central spine: 1-2, straight, erect, brownish, little longer and stouter than the others to 20-25 mm long.
Flowers: Very large, 4-6 cm in diameter (sometimes 9 cm broad), lemon yellow to straw-colored, with the outer segments tinged with red; perianth-segments glossy, linear-oblong, obtuse, outer ones entire, inner ones serrate and mucronate at apex; filaments orange-red; style red; stigma-lobes 6, linear, yellow.
Fruits: Oblong, to 25 mm long.

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
12) Del Weniger “Cacti of the Southwest: Texas, New Mexico, Oklahoma, Arkansas, and Louisiana” University of Texas Press, 1969

Cultivation and Propagation: Coryphantha octacanthaSN|3893]]SN|3893]] 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.