Coryphantha elephantidens
| Light | Bright light with some shade from harsh midday sun |
|---|---|
| Water | Moderately in the growing season; keep dry through a cool winter rest |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; USDA zones 9b–11 |
| Propagation | Seed (primary); occasionally from offsets on clustering plants |
| Toxicity | Non-toxic to cats and dogs |
Coryphantha elephantidens is a large, solitary, deep-green cactus from central and southern Mexico, prized for its plump, rounded tubercles that stack into a domed body and for the very large, showy flowers it produces in late summer and autumn. Its common name, elephant's tooth cactus, comes from those fat, blunt tubercles, which are said to resemble an elephant's molars. It is one of the boldest and most instantly recognisable members of the genus Coryphantha.
Description
Coryphantha elephantidens forms a solitary, flattened-globular to hemispherical plant, typically reaching around 15–25 cm across and up to about 15 cm high — distinctly broader than tall — though old specimens may grow larger and eventually offset to form clumps. The body is a rich, glossy green, densely covered in large, fat, rounded tubercles arranged in spiralling rows. Between the tubercles, especially toward the crown, the plant carries woolly felt that becomes more conspicuous in the flowering zone.
Each tubercle bears a cluster of stout, curved spines that are usually few in number, often amber to brownish and ageing grey. The spination is comparatively sparse for such a robust plant, leaving the plump green tubercles very much on display.
The flowers are the species' great attraction: large, funnel-shaped blooms in shades of pink to rose-purple, sometimes with a paler or darker throat, emerging from the woolly crown in late summer and autumn. They are among the largest flowers in the genus and open in succession over a period of weeks.
Distribution and habitat
The species is native to central and southern Mexico, where it grows on rocky slopes and in scrub and open woodland, often nestled among grasses and low shrubs that give it some shade and shelter. In habitat the plants root in gritty, well-drained ground and endure a marked dry season, drawing down on stored moisture in their fat tubercled bodies.
Like all cacti, the genus is listed under CITES Appendix II, which governs international trade. Nursery-grown plants are widely available and entirely legal to own and trade; wild collection is neither necessary nor appropriate.
Cultivation
Coryphantha elephantidens is a rewarding and fairly forgiving plant for a species with such an impressive appearance, but like most cacti it dislikes staying wet. Grow it in a very free-draining, mostly mineral mix in a pot only a little larger than the plant, and give it bright light with a little protection from the fiercest afternoon sun to keep the body firm and the tubercles plump.
Water moderately through the warm growing months, always letting the soil dry out between waterings, then keep the plant dry and cool over winter. This dry winter rest both prevents rot and helps trigger the following season's flush of flowers. Feed sparingly with a low-nitrogen cactus fertiliser during active growth. See Watering and Repotting for general technique.
Propagation
Seed is the usual and most reliable method, sown on a warm, gritty surface kept humid until germination; seedlings are steady rather than fast growers. Plants that have produced offsets can also be increased by removing a well-rooted pup, allowing the cut to callus, and potting it up. See Propagation — seed and Propagation — offsets for full walkthroughs.
Common problems
- Rot — the most common cause of loss, almost always from overwatering or a slow-draining mix; the plant softens and discolours from the base or crown.
- Corky or scarred tubercles — often cosmetic, from age, sun or cold spells, but persistent damage can invite rot.
- Pests — mealybugs (white fluff nestled between the tubercles and in the crown wool) and root mealybugs are the usual culprits; red spider mites may bronze the skin in hot, dry, still air. See Pests and diseases.
See also
- Coryphantha — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — seed · Propagation — offsets · Pests and diseases