Encephalocarpus strobiliformis
| Light | Bright light with some protection from the fiercest afternoon sun |
|---|---|
| Water | Very sparingly; allow to dry completely between waterings, keep dry in winter |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; roughly USDA zones 9b–11 |
| Propagation | Seed (primary) |
| Toxicity | Non-toxic to cats and dogs |
Encephalocarpus strobiliformis is a small, slow-growing cactus from northeastern Mexico, famous for the overlapping, keeled tubercles that give its body the look of a green pinecone — hence its common name, the pinecone cactus. Modern classifications place it within Pelecyphora as Pelecyphora strobiliformis, but it is still very widely grown and traded in the hobby under the older name Encephalocarpus strobiliformis.
Description
Encephalocarpus strobiliformis forms a small, mostly solitary plant, typically only a few centimetres across, whose most striking feature is its arrangement of tubercles. Rather than the rounded warts of many cacti, the tubercles are flattened, triangular and sharply keeled, pressed tightly against one another so that they overlap like the scales of a conifer cone. Each tubercle carries a tuft of woolly areole with only weak, soon-shed spines, so mature plants appear essentially spineless and smooth to the touch.
Much of the plant sits at or near soil level, with a substantial taproot below carrying it through drought. Flowers open from the woolly crown, usually in spring, and are comparatively large for the size of the body — funnel-shaped and violet to magenta-pink, a bright contrast against the muted green body.
Distribution and habitat
The species is native to a limited area of northeastern Mexico, in the states of Nuevo León and Tamaulipas, within the Chihuahuan Desert. It grows in arid limestone country, often rooting in gritty or rocky soils among low scrub and grasses that offer a little shade. Like many slow, highly ornamental cacti of the region, it contracts down toward the soil in dry conditions, which — together with its cone-like camouflage — makes wild plants inconspicuous and easily overlooked.
Unlike most cacti, which are listed under CITES Appendix II, this species falls under the stricter Appendix I, and habitat collection has put heavy pressure on natural populations. Nursery-grown, seed-raised plants are the responsible and legal source; collecting from the wild is not.
Cultivation
This is a connoisseur's plant that rewards patience and a light hand with water. Grow it in a very free-draining, mostly mineral mix, ideally with extra grit or limestone chips, in a pot deep enough to accommodate its taproot. Give it bright light with a little protection from the most intense afternoon sun, which helps keep the body compact and well-coloured.
Water thoroughly only when the soil has dried out completely, then allow it to dry again; overwatering, especially in a mix that holds moisture, is by far the commonest cause of loss. Keep the plant dry and cool through winter — this dry rest both prevents rot and encourages spring flowering. See Watering and Repotting for general technique.
Because it is naturally slow, some growers raise seedlings on faster grafting stock to build size before returning them to their own roots; grown hard on their own roots, plants stay small and take their natural form.
Propagation
Seed is the standard and by far the most reliable method. The fine seed is sown on a warm, gritty surface kept humid until germination, after which seedlings are grown on slowly and carefully. The species rarely offsets, so vegetative propagation is uncommon outside of grafting. See Propagation — seed for a full walkthrough.
Common problems
- Rot — nearly always from overwatering or a mix that stays wet; the plant softens and discolours, often from the base or taproot.
- Etiolation — too little light causes the body to stretch and lose its neat, cone-like symmetry.
- Pests — mealybugs (white fluff tucked among the woolly areoles) and red spider mites (fine webbing, bronzed skin) are the usual offenders. See Pests and diseases.
See also
- Encephalocarpus — the genus overview
- Pelecyphora — the genus into which this species is now placed
- Grafting · Soil and potting mix · Watering · Propagation — seed