Coryphantha elephantidens

Structure and identification

For the nominate subspecies, the monograph describes a flattened or spherical stem with large, rounded tubercles and thick lateral spines curving slightly towards the surface. White wool abundantly covers the young apex and grooves. The main root is thickened, and lateral roots are fibrous. Flowers range from pale purple to yellow. A single flower colour represents only part of the variation documented for the species. [Dicht and Lüthy 2005, p. 66–67]

Habitat and variation

Descriptions of the nominate subspecies cover a broad area of central and southern Mexico. The monograph associates it with plains and low ridges on lava substrates, among grasses, sometimes beneath shrubs or opuntias. The reproductive studies presented below were conducted in a specific population in tropical dry forest in Morelos. [Dicht and Lüthy 2005, p. 66–67; p. 103, sekcja 2.1] [Martínez-Peralta and Martínez-Zavala 2021, p. 66–67; p. 103, sekcja 2.1]

Flower sex and fruit set

In the population near Quilamula in Morelos, there were plants with bisexual flowers and plants with functionally female flowers. Stamens persisted as visible structures in female flowers, but their anthers produced no pollen. In a sample of 119 flowers observed in 2016–2018, female flowers accounted for 37%. This percentage concerns flowers in the sample. In 11 plants with several flowers open simultaneously, all flowers on each individual were of the same sex. The authors described the population as gynodioecious, comprising bisexual and female individuals. [Martínez-Peralta and Martínez-Zavala 2021, p. 104–108, sekcje 2.3, 3.1, ryc. 4]

In bisexual flowers, pollen was available on the first day, and the stigma became receptive the next day. This sequence is called protandry. Controlled self-pollination of 27 flowers produced no fruits. When pollinated with pollen from other plants, 63% of 27 flowers produced fruits, compared with 70% of 27 under open pollination. The material examined showed self-incompatibility, and natural insect visits provided fruit set similar to manual cross-pollination. [Martínez-Peralta and Martínez-Zavala 2021, pp. 104–105, 108–109, Section 3.2]

Bees visiting flowers of both sexes

Recordings from August 2018 covered 52 flowers on 48 plants, 26 flowers of each sex, and 944 minutes of observation. Mean visit frequency was 3.58 ± 3.20 per minute in bisexual flowers and 1.21 ± 1.03 in female flowers. The reported dispersion is the standard deviation. The most frequent group, Augochlorini bees, collected mainly pollen and touched the stigma relatively rarely. Ashmeadiella opuntiae often landed on the stigma and visited flowers of both sexes. Apis mellifera was recorded only in bisexual flowers. Visit frequency and stigma contact describe different elements of an insect's contribution to pollination. This study assessed behaviour, without measuring seed number after a single visit. [Martínez-Peralta et al. 2024, p. 1113–1119, tab. 1–2, ryc. 2–4]

Propagation in vitro

Bhau and colleagues compared whole young shoots 2 cm long, their tips, and transverse and longitudinal sections. Material was grown on MS medium with 3% sucrose and 0.8% agar, at pH 5.7, 25 ± 2°C and a sixteen-hour photoperiod. There were 20 explants per treatment, and experiments were repeated at least three times. After four weeks, longitudinal sections on medium with 1.5 mg/l BAP, a cytokinin that stimulates shoot formation, yielded a mean of 12.4 shoots per explant. At the same concentration, transverse sections yielded 6.9 shoots, tips 5.2, and whole shoots 1.0. [Bhau and Wakhlu 2015, p. 216–217, tab. 1]

Increasing BAP to 2 mg/l reduced the result for longitudinal sections to 4.6 shoots. The shoots produced were then transferred to MS without growth regulators, where the authors obtained rooting in all shoots included in this assessment. After five weeks of rooting, plants were transferred to a 1:1 mixture of sand and vermiculite and kept at elevated humidity for 14 days. Of 250 transferred plants, 238 survived, or 95.2%. The result describes a specific laboratory procedure and acclimatisation. The study did not examine the genetic fidelity of regenerants. [Bhau and Wakhlu 2015, p. 217–218, tab. 1–2, sekcje 3.3–3.4]

Subspecies bumamma in the anatomical study

The 2016 comparison of conducting tissues included two adult plants described as C. bumamma, now C. elephantidens subsp. bumamma. Their vessels in the tubercles had smaller diameters than vessels in the central vascular cylinder. The result concerns this subspecies and the pair of plants examined. The reproductive studies in Morelos and the micropropagation protocol use the species name without this qualification. [Terrazas et al. 2016, PDF pp. 2, 6, tables 1–2. POWO, subspecies bumamma, 11 October 2026] [2-WWW]

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