Echinopsis subdenudata
| Light | Bright, indirect to lightly filtered light; tolerates some direct sun with acclimation |
|---|---|
| Water | Regularly in the growing season once the soil dries; keep nearly dry and cool in winter |
| Soil | Fast-draining mineral-rich mix (see Soil and potting mix) |
| Temperature | Keep above freezing; hardy to roughly USDA zones 9–11 |
| Propagation | Offsets (primary) and seed |
| Toxicity | Non-toxic to cats and dogs |
Echinopsis subdenudata is a small, nearly spineless, dark-green globular cactus from the highlands of Bolivia, prized for the enormous, sweetly fragrant white flowers it throws up on long tubes during the warmer months. Its smooth body carries neat rows of pale, woolly areoles set into low ribs, and its easygoing nature and reliable blooming have made it one of the most popular beginner cacti in the hobby, sold under common names such as domino cactus and Easter lily cactus. It belongs to the large and free-flowering genus Echinopsis.
Description
Echinopsis subdenudata forms a solitary, flattened-globular body that slowly clusters with age, usually reaching around 8–12 cm across. The skin is a deep matte green and, unusually for a cactus, almost entirely without spines — hence the epithet subdenudata, "somewhat naked". The body is divided into a modest number of broad, rounded ribs, along which sit evenly spaced areoles filled with small tufts of white or greyish wool, giving the plant its tidy, dotted appearance and one of its common names, the domino cactus.
The flowers are the main attraction. They open from long, slender, hairy tubes that emerge from the areoles near the top and sides of the plant, unfurling into large funnel-shaped white blooms, often around 17–20 cm long including the tube — the open flower can be nearly as wide across as the plant's own body. They open in the evening, are strongly and sweetly scented, and last only a day or two, but a healthy plant will produce them in flushes through spring and summer.
Distribution and habitat
The species is native to Bolivia, where it grows on rocky slopes and among grasses in seasonally dry highland habitat. Plants there experience a warm, wetter growing season followed by a cool, dry winter — a rhythm worth imitating in cultivation to encourage flowering.
Cultivation
Echinopsis subdenudata is one of the most forgiving cacti for a beginner and flowers freely even as a young plant. Grow it in a free-draining, mostly mineral mix in a pot that is not too large, and give it bright light; it appreciates more water and feeding through the growing season than many desert cacti, provided the soil dries out between waterings. In its natural globular form it takes plenty of sun with acclimation, though very intense afternoon sun can scorch the spineless skin, so a little filtering does no harm.
The key to good blooming is a proper winter rest: keep the plant cool and nearly dry from late autumn, watering only enough to stop it shrivelling. This dry, cool dormancy sets the flower buds for the following season. See Watering and Repotting for general technique. The soft, spineless body is also commonly grafted in the hobby (see Grafting).
Propagation
The easiest method is by offsets: mature plants pup freely around the base, and these can be twisted or cut off, left to callus for a few days, and potted into a gritty mix where they root quickly. The species also comes readily from seed, germinating easily on a warm, humid mineral surface, which is how growers raise large batches and how many of the showier Echinopsis hybrids are produced.
Cultivars
While the plain species is grown mostly for its own charm, E. subdenudata sits within a genus that has been hybridised extensively for spectacular flower colour. A well-known selected form, sold as Echinopsis subdenudata 'Fuzzy Navel, is distinguished by unusually dense white wool in the areoles, giving the body a softer, fuzzier look than the standard form. See the Echinopsis genus page for an overview of the hybrid groups.
Common problems
- Rot — the commonest cause of loss, almost always from overwatering, a poorly draining mix, or water sitting in the crown in cool weather; the body softens and discolours from the base or centre.
- Etiolation — too little light makes the body pale and stretch into an unnatural column instead of staying flat and globular.
- Shy flowering — usually the result of skipping the cool, dry winter rest, or of too little light through the growing season.
- Pests — mealybugs (white fluff in the areoles and around the roots) and red spider mites (fine webbing, bronzed skin) are the usual offenders; see Pests and diseases.
See also
- Echinopsis — the genus overview
- Grafting · Soil and potting mix · Watering · Propagation — offsets · Propagation — seed