Cactus rustico che resiste fino a - 10° C (se asciuto). Ha lunghe spine scure e ramifica abbondantemente fino a formare con il tempo colonie di un metro in diametro.
Family: Cactaceae (Cactus Family)
Scientific name: Coryphantha macromeris (Engelmann) Lemaire, Cactées. 35. 1868
- Mammillaria macromeris Engelmann in F. A. Wislizenus, Mem. Tour N. Mexico, 97. 1848;
- Coryphantha macromeris var. runyonii (Britton & Rose) L. D. Benson;
- Coryphantha macromeris subsp. runyonii (Britton & Rose) N. P. Taylor;
- Coryphantha pirtlei Werdermann;
- Coryphantha runyonii Britton & Rose;
- Lepidocoryphantha macromeris (Engelmann) Backeberg
Origin: New Mexico, Texas ; Mexico (Chihuahua, Coahuila, Durango, Zacatecas).
Habitat: grows nearly in all substrates including nearly pure gypsum, gravelly soils, usually sandy alluvium or clay, rarely crevices or steep slopes; 30-1700(-2000) m.
Coryphantha macromeris DJF1353 El Paso, TX.
It is a hardy cactus with long, dark spines which branches profusely, ultimately forming low mats or hemispheric mounds to 100 cm diameter.
Description: Plants profusely branched with long projecting spines, ultimately forming low mats or hemispheric mounds to 100 cm diameter
Stem: Noticeably tuberculate, hemispheric to short cylindrical, sometimes obscured by profusion of immature branches, 4-12 cm; tubercles unusually large 15-25 mm and grooved only on the upper half, flaccid or flabby; areolar glands seasonally conspicuous;
Root: It has deep succulent taproot often massive and large.
Spines: Weakly appressed or projecting, slightly curved, often flexible. Radial 9-15 per areole, white, grey, tan, or brown, 15-25 mm long; subcentral spines 2-3 in adaxial part of areole; central spines 3-8 per areole, pale grey to black, abaxial central spine porrect or descending,
Flowers: Apical or nearly so at mid-level of tubercle, outer tepals heavily fringed; flower bright rose-pink or magenta, often with darker midstripes and paler margins
Fruits: Dark green, ovoid to obpyriform or ellipsoid.
Note (1): C. macromeris pass several stages of development in which their appearance changes and stunted or immature plants are variable, often have only 5-7 radial spines and lacking central spines. It has strongly mucilaginous cortex even small slices of living tubercle tissue are visibly and tangibly slimy.
Notes (2): The flowers of C. macromeris are virtually identical to those of Mammillaria wrightii and Escobaria vivipara; in the absence of vegetative material, flowers may be unidentifiable.
Cultivation: 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). Very 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.