Name and rib number of the material examined
The accepted name is Stenocactus coptonogonus (Lem.) A.Berger. Echinofossulocactus coptonogonus is a synonym. An analysis of 53 adult plants from three populations found 12–14 complete ribs, averaging 13 ± 0.39, expressed as mean ± standard deviation. This trait distinguished the material from parental plants with numerous ribs and from S. × irregularis. [2-WWW] [González-Zamora et al. 2023, POWO; p. 90–95, tabela V]
Tree shelter and seedling response
Pérez-Sánchez and colleagues transferred four- to five-week-old seedlings beneath mesquite canopies and to an open area in San Juanico Chico, at 1870 m. Five replicates of 41 seedlings were planned for each treatment. Chlorophyll fluorescence, mass, photosynthetic area and relative water content were assessed over 105 days. [Pérez-Sánchez et al. 2015, pp. 3–4]
The results text for S. coptonogonus indicates higher effective photosystem II yield in shade, with higher estimated electron transport in sunlight. Mean relative water content was 55.55 ± 1.56% beneath trees and 62.68 ± 1.35% in the open area, expressed as means ± standard error. During this period, no significant microenvironment effect was found on relative growth rate or mass increase per unit photosynthetic area. [Pérez-Sánchez et al. 2015, pp. 5, 7, appendix, data on pp. 14, 16–20]
Two-year-old plants in warming chambers
In the 2013 experiment, 120 two-year-old plants per treatment were placed in six OTC chambers and six control plots. Plants remained in pots, four per container, on cleared former farmland, without watering during the trial. Chambers increased daytime temperature and reduced air relative humidity. [Aragón-Gastélum et al. 2017b, pp. 94–95]
After 105 days, all S. coptonogonus in the chambers were dead, while more than 22% remained alive in the control. The result indicates this material's sensitivity to the combined chamber conditions. It covers young, transplanted plants in an exposed area and does not establish an independent thermal threshold for adult cacti. [Aragón-Gastélum et al. 2017b, p. 95–97, ryc. 2]
Shoots from areoles in tissue culture
In Pérez Molphe Balch and colleagues' study, explants of the species came from aseptically germinated seedlings. On MS medium with BA 1 mg/l, a mean of 16.75 ± 2.47 shoots per explant was obtained, with standard error reported. Cultures were kept at 25 ± 2°C, with a sixteen-hour photoperiod and 54 µmol photons m⁻² s⁻¹. Multiplication treatments had three replicates, with 5–20 explants depending on the species. [Pérez Molphe Balch et al. 1998, pp. 131–133, Table 1]
In the best rooting treatment, with IBA 1 mg/l, 90% of shoots rooted. Four weeks after transfer to substrate, 80% of the batch previously rooted in vitro and 75% of a separate batch rooted ex vitro survived. Survival-assessment batches contained 20 shoots each. These three values describe separate stages and treatments in the process. [Pérez Molphe Balch et al. 1998, pp. 132–134, Table 2]
Related articles
Materials from the author's archive
The species also appears in Konrad Szychowski's private material archive. [Cactáceas y Suculentas Mexicanas 1959, file p. 18]
Synonyms and names in the literature
Brittonrosea coptonogona · Echinocactus coptonogonus · Echinocactus coptonogonus var. major · Echinocactus interruptus · Echinofossulocactus coptonogonus · Echinofossulocactus coptonogonus var. major · Efossus coptonogonus · Ferocactus coptonogonus [2-WWW]