Coryphantha pallida
| Light | Bright light to full sun; strong light keeps growth compact |
|---|---|
| Water | Moderately in the growing season; allow to dry fully between waterings, keep dry in winter |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; USDA zones 9b–11 |
| Propagation | Seed; division of offsets where clumps have formed |
| Toxicity | Non-toxic to cats and dogs |
Coryphantha pallida is a small, slow-growing cactus from south-central Mexico with globular, glaucous grey-green stems clothed in pale, interlacing spines. Usually solitary, it offsets in age to form small groups of heads. Each stem is crowned in season by large, pale lemon-yellow flowers whose narrow outer segments are backed with a reddish stripe, making a well-flowered plant one of the more striking members of the genus Coryphantha.
Description
Coryphantha pallida begins as a solitary globe and, with age, may offset to form small groups of a dozen or so heads. Individual stems are firm, globose to obovate, and up to around a hand's width across (roughly 8–12 cm), covered in the spiral of tubercles typical of the genus.
The spines are the plant's most distinctive feature: the numerous radials are pale, chalky to whitish, and spread so that those from neighbouring areoles interlace across the body, partly veiling the green skin beneath. Mature plants also carry a few stouter central spines, which are sometimes dark- or black-tipped.
Flowers appear from the growing tips in late spring and summer, opening wide in bright light. They are comparatively large for the plant — around 6–7 cm across — pale lemon-yellow, the narrow outer segments carrying a reddish dorsal stripe, and a mature plant can carry several open at once.
Distribution and habitat
The species is native to the semi-arid highlands of south-central Mexico, in the states of Puebla and Oaxaca — chiefly the Tehuacán–Cuicatlán Valley — where it grows on calcareous, alluvial gravels among low deciduous woodland and xerophytic scrub. In habitat it experiences strong sun, sharp drainage and a pronounced dry season, conditions worth keeping in mind when growing it.
Like all cacti it is listed under CITES Appendix II, so international trade is regulated; nursery-raised plants are the proper source, and collecting from the wild is neither necessary nor permitted.
Cultivation
Coryphantha pallida is a rewarding, undemanding plant for a sunny spot. Grow it in a very free-draining, mostly mineral mix and give it as much light as you can — strong light keeps growth tight and the pale spination dense, while too little causes soft, stretched growth. Water moderately through the warm months once the mix has dried out, then keep the plant dry and cool over winter to prevent rot and encourage flowering. See Watering and Repotting for general technique.
As offsets accumulate, established plants slowly outgrow their pots; lift and divide crowded groups at repotting time if you want to keep them shapely or increase your stock.
Propagation
Seed is the primary method and germinates readily on a warm, gritty surface kept lightly humid; see Propagation — seed. Where the plant has offset, established groups can also be increased by division — separate rooted heads, let the cut surfaces callus, then pot them up as you would rooted offsets.
Common problems
- Rot — the usual cause of loss, almost always from overwatering or a slow-draining mix, especially in cold weather; heads soften and discolour from the base.
- Etiolation — too little light makes stems pale and elongate, and the compact habit is lost.
- Pests — mealybugs (white fluff in the tubercle axils and roots) and red spider mites are the common offenders; see Pests and diseases.
See also
- Coryphantha — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — seed · Propagation — offsets