Origin and Habitat: New Mexico (Garfield, Dona Ana, and Sierra County), USA
Altitude range: Around 1850 metres above sea level.

• Coryphantha scheeri var. valida (Engelm.) L.D.Benson in L.D.Benson
• Mammillaria scheeri var. valida Engelm.

• Coryphantha robustispina (A.Schott ex Engelm.) Britton & Rose
• Cactus brownii Toumey
• Cactus robustispinus (A.Schott ex Engelm.) Kuntze
• Coryphantha muehlenpfordtii subs. robustispina (A.Schott ex Engelm.) Dicht
• Coryphantha muehlenpfordtii var. robustispina (Schott ex Engelm.) W.T.Marshall
• Coryphantha scheeri var. robustispina (A.Schott ex Engelm.) L.D.Benson
• Mammillaria brownii Toumey
• Mammillaria robustispina A.Schott ex Engelm.
• Coryphantha muehlenpfordtii (Poselg.) Britton & Rose
• Echinocactus muehlenpfordtii Poselg.

• Coryphantha robustispina subs. scheeri (Muehlenpf.) N.P.Taylor
• Cactus scheeri (Muehlenpf.) Kuntze
• Coryphantha scheeri (Muehlenpf.) Lem.
• Mammillaria scheeri Muehlenpf.
• Coryphantha neoscheeri Backeb.
• Coryphantha scheeri var. valida (Engelm.) L.D.Benson in L.D.Benson
• Mammillaria scheeri var. valida Engelm.
• Mammillaria engelmannii Cory

• Coryphantha robustispina subs. uncinata (L.D.Benson) N.P.Taylor
• Coryphantha muehlenpfordtii subs. uncinata (L.D.Benson) Dicht
• Coryphantha scheeri var. uncinata L.D.Benson

Description: Coryphantha scheeriSN|10314]]SN|10315]] v. valida is the New Mexican form of the widespread Coryphantha robustispina subs. scheeriSN|10314]]SN|10314]] (= Mammillaria scheeriSN|10325]]SN|10325]] Mühlenpfordt 1845). The var. valida was firstly described as Mammillaria scheeriSN|10325]]SN|10325]] var. valida by Engelmann in 1856 without having seen Mammillaria scheeriSN|10325]]SN|10325]] Mühlenpfordt. Engelmann had presumed that his var. valida might be just a somewhat larger and more heavily spined northern form of Mammillaria scheeriSN|10325]]SN|10325]] (from Chihuahua in northern Mexico). When visiting the collection of Prince Salm-Dyck, he found original plants of Mammillaria scheeriSN|10325]]SN|10325]] which corresponded completely with his var. valida, thus confirming his initial assumption. As Engelmann himself had realised already, var. valida does not contain enough distinct criteria to delineate a variety or subspecies and it should be fully synonymized with Mammillaria scheeriSN|10325]]SN|10325]] (Coryphantha robustispina subs. scheeriSN|10315]]SN|10314]]).

Bibliography: Major references and further lectures
1) Reto Dicht, Adrian Lüthy Coryphantha: Cacti of Mexico and Southern USA (Google eBook) Springer Science & Business Media, 14 March 2006
2) Nathaniel L. Britton, J. N. Rose “Cactaceae: Descriptions and Illustrations of Plants of the Cactus” Volume IV. The Carnegie Institution of Washington Washington, 24/Dec/1923
3) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
4) 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
5) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
6) Heil, K. & Corral-Díaz, R. 2013. Coryphantha robustispina. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 23 April 2015.

Cultivation and Propagation: This plant grows in the same habitat as Echinocactus horizonthaloniusSN|1711]]SN|1711]], with which it has some cultivation problems in common: slow-growing, seldom reaching the same size as in nature, sensitive against over-watering (does better when grafted). Water sparingly. It needs good drainage. Keep drier in winter. Full sun to partial shade. In humid conditions, the exudation of nectar (if not completely removed by ants) can cause the formation of mould, which leads to ugly black-colouring of the epidermis. To prevent this, spray the plant with water to remove the nectar. And provide very good ventilation.
Frost hardiness: Can withstand temperatures down to -6,6º C. (or less for short periods).
Propagation: Seeds or grafting.