Turbinicarpus pseudopectinatus
| Light | Bright light with a little shade from the fiercest afternoon sun |
|---|---|
| Water | Very sparingly; allow the mix to dry completely between waterings, keep dry in winter |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; a cool, dry winter rest suits it well |
| Propagation | Seed (primary); occasionally grafted to speed young plants |
| Toxicity | Non-toxic to cats and dogs |
Turbinicarpus pseudopectinatus is a small, slow-growing cactus from the gravelly, calcareous soils of northeastern Mexico. Its neat, comb-like white spines lie flat and pressed against the body in tidy rows, cloaking the whole plant so completely that it can resemble a tiny feathered pincushion, and in spring it opens surprisingly large flowers of pale pinkish-white to pink, each petal marked with a darker magenta stripe. Long shuffled between several genera, it is a much-loved miniature among collectors of Turbinicarpus.
Description
Turbinicarpus pseudopectinatus forms a small, solitary body that is roughly globular to shortly cylindrical and seldom more than a few centimetres across. The plant is built from many small tubercles arranged in spiralling rows, and each areole carries a dense row of short, fine, pectinate (comb-like) marginal spines with no central spine. These spines are white to pale, held flat against the tubercles and interlocking neatly, so the surface looks combed and almost furry rather than fiercely armed.
Flowers appear from near the crown, mostly in late winter and spring. They are comparatively large for so small a plant, funnel-shaped, and are pinkish-white to pink, each tepal carrying a darker magenta or reddish midstripe. Like other members of the genus it has a stout taproot that anchors it and stores water, an adaptation to its lean, seasonal habitat.
Distribution and habitat
The species is native to northeastern Mexico, in the states of Coahuila, Nuevo León, San Luis Potosí and Tamaulipas. It grows on gravelly, calcareous soils, in grassland and pinyon-juniper woodland, often wedged among rocks and low vegetation that give it a little shade and shelter. In habitat plants sit low, with much of the body at or below the soil surface, drawing down into the ground during drought and swelling again after seasonal rains.
Like the whole cactus family, Turbinicarpus is listed under CITES, but the genus is placed on the stricter Appendix I — rather than the Appendix II that covers most cacti — because of its small, localised populations and pressure from illegal collection. Nursery-propagated plants are widely and legally available; wild plants should never be collected.
Cultivation
T. pseudopectinatus is a rewarding miniature but unforgiving of excess moisture, and rot is by far the commonest cause of loss. Grow it in a very free-draining, mostly mineral mix with generous grit, in a pot deep enough to accommodate the taproot. Give it bright light with only light shading in the hottest part of summer; too little light spoils the tight, symmetrical spination.
Water thoroughly only when the mix has dried out completely, and taper off in autumn so the plant can take a dry, cool winter rest. That dry rest both encourages spring flowering and greatly reduces the risk of rot. See Watering and Repotting for general technique, and take care when repotting not to snap the brittle taproot.
Propagation
Seed is the standard and most reliable method. The fine seed germinates well on a warm, mineral surface kept humid until the seedlings establish; growth is slow, so patience is needed. The species rarely offsets, so vegetative propagation is uncommon, though growers sometimes graft seedlings onto a vigorous rootstock to speed them along before returning them to their own roots. See Propagation — seed for a full walkthrough.
Common problems
- Rot — nearly always from overwatering, a slow-draining mix, or moisture during the cold months; the body softens and discolours, often from the base.
- Etiolation — too little light causes the plant to swell and lose its tight, combed spine pattern.
- Pests — mealybugs (white fluff among the tubercles and on the roots) and red spider mites are the usual offenders; inspect the root system as well as the top.
See also
- Turbinicarpus — the genus overview
- Grafting · Soil and potting mix · Watering · Propagation — seed · Repotting · Pests and diseases