Coryphantha ELEPHANTIDENS

Coryphantha ELEPHANTIDENS - Elephant tooth cactus, Coryphantha elephantidens.

Coryphantha is a genus of globose or shortly cylindrical cacti in the cactus family (Cactaceae), comprising about sixty species distributed from the southwestern United States throughout Mexico. They grow in deserts, semi-deserts, and savannas, on rocky and volcanic slopes. Species from southern Mexico are considered the easiest in cultivation, whereas northern and North American ones are noticeably more finicky.

The stem is covered with large tubercles, complemented in desert species by stout spines, both of which help the plant retain moisture in an arid climate. In adult specimens, a characteristic groove runs along the upper side of the tubercle from the areole - its appearance signifies that the plant has reached blooming age.

Almost all species bloom regularly, from summer until late autumn, with large flowers up to 6 cm (2.4 in) across, most often yellow. Initial flowering usually occurs not earlier than five years of age; in slow-growing species, more than ten years pass from sowing to the first flower. After flowering, juicy berry-like fruits form.

The elephant tooth cactus is a species endemic to Mexico, where it grows on volcanic slopes of the states of Michoacán, Morelos, Guerrero, and several neighboring ones. It is considered the best known and perhaps the most unpretentious member of the genus. The stem is flattened-globose, up to 14 cm (5.5 in) in height and 19 cm (7.5 in) across, solitary, with age sometimes forming small clusters.

The tubercles are very large, thick, slightly flattened, up to 4 cm (1.6 in) long, with dense wool in the axils. There are about eight spines, up to 2 cm (0.8 in) long, stout, yellowish, turning brownish over time. The flowers are large, 6-11 cm (2.4-4.3 in) across, bright pink or purple, rarely white with a red throat.

Coryphantha seeds are small, brown or almost black, with a shiny surface, ripening in juicy berry-like fruits. Soaking such seeds is impractical - they easily get lost in liquid, so the substrate itself is disinfected: before sowing, it is drenched with a weak potassium permanganate solution and dried. Scarification and stratification are not required.

Sowing is carried out on the surface, over a moistened mineral mixture of sand and fine perlite - seeds are only lightly pressed into the surface without burying. The sowing is moistened with a spray bottle using a growth stimulant solution: SUPERthrive, HB-101, Aminozol, Epin, or Zircon, covered with glass or film or placed in a propagator, and kept in indirect light at a temperature of 22-26 °C (72-79 °F) with regular ventilation.

Under favorable conditions, initial sprouts emerge in as little as a week; main germination usually takes 3-4 weeks, while individual seeds may delay for longer than a month. Seedlings grow slowly and are very sensitive to overwatering. Pricking out is conducted after the first spines appear, into individual small pots with mineral substrate.

© Greeniverse. All rights reserved.

Coryphantha needs bright lighting with direct sun. The plant rarely suffers sunburn - in response to bright light it increases woolliness and produces longer, denser spines, which only adds to its ornamental value. Good air circulation and regular ventilation are mandatory.

In summer the plant is kept in warmth; in winter it requires a dormant period for several months at a temperature of 4-12 °C (39-54 °F). In completely dry substrate, hardened plants also tolerate brief sub-zero temperatures, but one should not deliberately aim for this.

In summer, watering is regular after complete drying of the substrate. In winter, during dormancy, watering is stopped completely - it is specifically dry cold overwintering that ensures abundant flowering in the following season. The combination of moisture and low temperature is fatal to coryphantha.

The substrate must be mineral, loose, and fast-drying: ready-made cactus soil with the addition of coarse sand, perlite, or zeolite. Good drainage is mandatory. Coryphantha has a stout taproot, so a sufficiently deep pot is selected.

Feeding is carried out only during active growth, once a month with a low-nitrogen fertilizer for cacti and succulents. Fertilizers are not applied during dormancy.

Repotting is carried out as the plant outgrows its pot, into dry substrate, after which the plant is given several days to settle before the first watering.