Euphorbia abdelkuri
| Light | Bright light to some direct sun; tolerates light shade |
|---|---|
| Water | Sparingly; let the mix dry fully between waterings, keep dry and warm in winter |
| Soil | Very free-draining mineral mix (see Soil and potting mix) |
| Temperature | Warmth-loving; keep above ~10 °C, no frost (roughly USDA zones 10b–11) |
| Propagation | Cuttings and grafting; seed where available |
| Toxicity | Toxic — the latex is caustic and irritating to skin, eyes and mucous membranes, and harmful if ingested |
Euphorbia abdelkuri is a slow-growing succulent from the Socotra archipelago, off the Horn of Africa, named for the small island of Abd al Kuri where it grows. It forms upright, candle-like columns coated in a chalky grey, almost waxy skin, and is unusual among euphorbias in bleeding a distinctly yellow latex rather than the milky white sap typical of the genus. Its strange, mineral-grey stems have made it a prized collector's plant, especially in the sought-after pink-flushed sport known as Damask.
Description
Euphorbia abdelkuri grows as a cluster of erect, cylindrical stems that branch sparingly from the base, giving the plant the look of a bundle of pale candles. The stems are nearly spineless and only faintly ribbed, their surface a soft grey-green overlaid with a pruinose, wax-like bloom that can look almost stony. Old plants slowly build into a low, columnar clump.
Like other members of Euphorbia, the flowers are tiny and enclosed in specialised cup-shaped structures called cyathia, borne toward the stem tips; they are modest and greenish-yellow rather than showy. The most talked-about feature is the sap: where most euphorbias exude white latex, E. abdelkuri oozes a striking yellow latex when cut — it is the only species in the genus known to do so. This latex is caustic and should be treated with care (see below).
Distribution and habitat
The species is endemic to the Socotra archipelago in the Indian Ocean, in particular the island of Abd al Kuri, part of Yemen. This is an arid, wind-scoured landscape of limestone rock with very low, seasonal rainfall, and the plant's chalky, water-conserving stems reflect that harsh, sun-baked environment.
As with many island endemics, wild populations are limited in range and vulnerable to disturbance. Like other succulent euphorbias, the species is listed under CITES (Appendix II), so international trade in wild-collected material is regulated; nursery-propagated plants are the appropriate and legal source for collectors.
Cultivation
Euphorbia abdelkuri is grown much like other columnar desert euphorbias: give it warmth, strong light and a very free-draining, mostly mineral mix. It resents cold, wet conditions, so water thoroughly only when the mix has dried out, and keep the plant nearly dry and warm through winter. It is naturally slow, and patience is part of owning one.
Bright light keeps the grey stems firm and compact; too little encourages weak, drawn growth. Protect it from frost entirely. See Watering and Repotting for general technique. When handling or cutting the plant, wear gloves and eye protection because of the irritant latex.
Propagation
The plant can be propagated from stem cuttings, though the caustic yellow latex makes this messier than with many succulents; allow cuttings to callus well before setting them on a dry, gritty surface to root. Because the species is slow and can be temperamental on its own roots, growers almost always use grafting onto a vigorous columnar rootstock — most commonly Euphorbia canariensis — to speed growth and to keep the slow-rooting 'Damask' sport thriving. Seed is used where it can be obtained.
Cultivars
The best-known selection is Damask, a naturally occurring sport (first noted around 1999) in which the body flushes pinkish-red — deepening under bright light — while the ribs stay grey, giving a two-toned effect that recalls the rosy tone of damask. Like the species itself, it is almost always grown grafted, since abdelkuri is slow and difficult on its own roots; give it bright light to hold the colour. Care otherwise follows the species.
Common problems
- Rot — the usual killer, brought on by overwatering, a slow mix or cold, damp winters; stems soften and discolour from the base.
- Etiolation — too little light produces thin, stretched, weakly coloured growth instead of firm grey columns.
- Latex irritation — the yellow sap is caustic and can burn skin and especially eyes; keep it away from children and pets and wash off any contact promptly.
- Pests — mealybugs (white fluff around the growing points and roots) and the occasional spider mite are the main nuisances; see Pests and diseases.
See also
- Euphorbia — the genus overview
- Grafting · Soil and potting mix · Watering · Propagation — cuttings · Repotting · Pests and diseases