Haageocereus acranthus
| Light | Full sun to very bright light |
|---|---|
| Water | Regular in warm growth; keep dry and cool in winter |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; best in USDA zones 9b–11 |
| Propagation | Seed; cuttings of stem segments |
| Toxicity | Non-toxic to cats and dogs |
Haageocereus acranthus is an erect, columnar cactus native to the coastal deserts of central Peru, forming clumps of ribbed green stems clothed in dense, often yellowish to golden spines. It bears funnel-shaped, greenish-white flowers that open at night, a hallmark of the genus Haageocereus and a feature that makes this an eye-catching addition to any collection of Peruvian columnar cacti.
Description
Haageocereus acranthus grows as an upright column, usually branching from the base to form a small cluster of stems that can reach roughly one to two metres in height in habitat, more modest in a pot. Each stem is cylindrical and divided into about twelve to fourteen low ribs, along which sit closely spaced areoles.
The spination is the plant's defining ornament: numerous fine, needle-like yellow radial spines together with a longer, stouter central spine that points downward, ranging in colour from pale straw and honey-yellow to reddish or brownish tones, sometimes densely enough to veil the green body. As with many Haageocereus, the spine colour can vary noticeably between individual plants and populations.
Flowers appear from areoles near the stem tips. They are funnel-shaped, greenish-white and open through the night, with anthesis often extending into the following morning — a form typical of night-blooming desert cacti, which here are pollinated chiefly by bats and hawk (sphingid) moths. Flowering is followed by rounded, fleshy fruit.
Distribution and habitat
The species is endemic to Peru, where it grows on the arid Pacific-facing slopes and coastal hills of the central part of the country. This is a landscape of sparse desert vegetation nourished largely by seasonal coastal fog (lomas) rather than regular rainfall, and the cactus is well adapted to long dry spells punctuated by humid periods. Plants typically root in rocky or gritty, sharply drained ground in bright, exposed positions.
Cultivation
Haageocereus acranthus is a rewarding and reasonably straightforward columnar cactus for a grower who can give it strong light. Provide the brightest position available — full sun suits it well and encourages the dense, well-coloured spination the species is grown for. Weak light produces thin, pale, etiolated growth.
Grow it in a gritty, mostly mineral mix that drains freely, and water regularly through the warm growing season once the soil has dried, then reduce sharply. Keep the plant dry and cool over winter to prevent rot and to help set flowers. Good airflow and a snug but stable pot suit it. See Watering and Repotting for general technique.
Propagation
Propagation is by seed or by cuttings. Seed germinates well on a warm, humid mineral surface and is the usual way to raise numbers; see Propagation — seed. Because the plant clusters and offsets, stem segments can also be taken, left to callus in a dry, shaded spot for a week or two, and then rooted in a barely moist gritty mix — see Propagation — cuttings and Propagation — offsets.
Common problems
- Rot — the most common killer, almost always from overwatering, a slow-draining mix, or cold wet winter conditions; stems soften and discolour from the base.
- Etiolation — too little light causes thin, stretched, pale growth with sparse spines, spoiling the plant's stout columnar form.
- Pests — mealybugs (white fluff in the areoles and around the roots) and red spider mites (fine webbing and a bronzed sheen) are the usual offenders. See Pests and diseases.
See also
- Haageocereus — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — cuttings · Repotting