Haageocereus multangularis
| Light | Full sun to very bright light |
|---|---|
| Water | Moderate in the growing season; keep dry and cool in winter |
| Soil | Fast-draining, mostly mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; protect from hard frost (roughly USDA zones 9b–11) |
| Propagation | Seed; cuttings of stem segments |
| Toxicity | Non-toxic to cats and dogs |
Haageocereus multangularis is a many-ribbed, columnar cactus from the coastal deserts of Peru, grown for its dense coat of colourful golden to reddish spines and its white, night-opening flowers. A classic desert-coast species and one of the better-known members of the genus Haageocereus, it forms clustering or erect stems clothed so thickly in spines that the green body is often nearly hidden.
Description
Haageocereus multangularis is a columnar cactus whose stems are cylindrical and heavily ribbed, typically with a high number of low, closely set ribs — the "many-angled" trait that gives the species its name. Depending on the population and growing conditions the stems may stand erect, lean, or sprawl and root along the ground, branching from the base to form clumps over time.
The ribs carry closely spaced areoles bearing numerous fine, needle-like spines. Spine colour is the plant's chief ornamental feature and varies from bright golden-yellow through honey and amber to reddish or brownish tones, often with the central spines longer and darker than the radials. In strong light the spination can be dense enough to give the whole stem a warm, glowing sheen.
Flowers are nocturnal, opening at night and into the cool of the following morning. They are funnel-shaped and white to cream, borne toward the upper part of the stems, and are followed by fleshy fruits. As with many night-blooming cacti, the flowers are relatively short-lived but can appear in numbers on established plants.
Distribution and habitat
The species is native to Peru, where it grows in the arid coastal desert and on the dry western slopes above it. This is a landscape of extreme rainfall scarcity, where much of the available moisture arrives as coastal fog (the lomas phenomenon) rather than as rain. Plants root in sandy, gritty and rocky ground in full exposure, enduring intense sun, drought and the salt-laden air of the desert coast.
Haageocereus taxonomy is notoriously tangled, and populations spanning the Peruvian coast have been described under many names; H. multangularis has at times been circumscribed broadly to include a range of variable forms.
Cultivation
Haageocereus multangularis is a rewarding grower that wants what its habitat provides: strong light and sharp drainage. Give it the sunniest position you can and a very free-draining, mostly mineral mix. The brightest light brings out the best spine colour and keeps the stems stout and true to form.
Water moderately through the warm growing season, letting the mix dry well between drinks, then keep the plant dry and cool over winter to encourage flowering and prevent rot. Like most coastal desert cacti it tolerates heat and drought far better than it tolerates wet, cold feet. Protect it from hard frost; it is not reliably cold-hardy. See Watering and Repotting for general technique.
Propagation
The species can be raised from seed, which germinates readily on a warm, gritty surface kept lightly humid, and is also easily grown from cuttings. A stem segment cut and allowed to callus for a week or two before potting into a dry, mineral mix will usually root without difficulty in warm conditions. Clumping plants can likewise be divided.
Common problems
- Rot — the usual killer, brought on by overwatering, a slow-draining mix, or winter wet; stems soften and discolour, often from the base.
- Etiolation — too little light makes new growth thin, pale and weakly spined, spoiling the dense golden spination that is the plant's main appeal.
- Pests — mealybugs (white fluff among the spines and at the roots) and red spider mites (fine webbing, bronzed skin) are the most common; see Pests and diseases.
See also
- Haageocereus — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — cuttings · Repotting