Haageocereus pseudomelanostele
| Light | Full sun to bright light; loves as much sun as you can give it |
|---|---|
| Water | Moderate in the growing season; keep dry and cool in winter |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; hardy to roughly USDA zones 9b–11 |
| Propagation | Seed; cuttings of the columns |
| Toxicity | Non-toxic to cats and dogs |
Haageocereus pseudomelanostele is a variable columnar cactus from the coastal deserts and western Andean slopes of Peru, clothed in dense golden to reddish-brown spines that can all but hide the green body beneath. It is one of the most commonly grown and widely offered species of the genus Haageocereus, valued for the warm, glowing colour of its spination and its comparatively easy-going nature in cultivation.
Description
Haageocereus pseudomelanostele forms erect to slightly leaning columns that branch mainly from the base to make loose clumps, with individual stems reaching up to roughly 70 centimetres in height and up to around eight centimetres in diameter. The stems are ribbed, with numerous low, closely set ribs carrying evenly spaced areoles.
The spines are the plant's chief attraction and the source of most of its variability. Each areole bears a dense cluster of fine radial spines together with longer central spines, in shades ranging from pale straw and honey-gold through amber to deep reddish-brown; the overall colour and density differ markedly from one clone to the next, and named forms have been selected for particularly bright or coppery spination.
Flowers are borne near the stem tips and open at night, funnel-shaped and typically white, sometimes with darker reddish to purplish outer segments, followed by rounded fleshy fruit. As with many night-flowering columnar cacti, blooms tend to appear on more mature, well-established plants.
Distribution and habitat
The species is native to Peru, where it grows in the arid coastal lomas and on the dry lower slopes of the western Andes. It is at home in extremely dry, bright, mineral-rich ground, drawing much of its moisture from seasonal fog and sparse rainfall rather than regular rain.
H. pseudomelanostele is a variable and much-debated species, and a good deal of the taxonomic confusion in Haageocereus involves plants that have at various times been treated as separate species or subspecies (see the synonyms below). In the wild it grows among other desert-adapted plants on open, sun-baked terrain.
Cultivation
This is one of the more forgiving members of its genus and a good introduction to columnar cacti. Grow it in a very free-draining, mostly mineral mix and give it as much sun as you can — strong light is what keeps the spines dense and richly coloured and the stems sturdy rather than drawn.
Water moderately through the warm growing season, letting the mix dry out well between waterings, then keep the plant dry and cool over winter. A cool, dry winter rest both reduces the risk of rot and helps encourage flowering in mature plants. Like most desert cacti it resents cold, wet roots, so protect it from freezing and from prolonged damp. See Watering and Repotting for general technique.
Propagation
H. pseudomelanostele can be raised from seed or grown on from cuttings. Seed germinates readily on a warm, mineral surface kept humid, giving the most genetic variety — useful given how variable the species is. Columns or branches can also be removed and rooted: let the cut surface callus for several days to a couple of weeks in a dry, shaded spot, then set the cutting on barely moist mineral mix until roots form. See Propagation — seed and Propagation — cuttings for full walkthroughs.
Common problems
- Rot — usually the result of overwatering or a slow-draining mix, especially in cool weather; stems soften and discolour, often from the base.
- Etiolation — too little light produces pale, thin, weakly spined growth that loses the species' characteristic dense golden coat.
- Pests — red spider mites (fine webbing and bronzed skin, favoured by hot dry air) and mealybugs (white fluff tucked among the spines and areoles) are the most common. See Pests and diseases.
See also
- Haageocereus — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — cuttings · Repotting · Pests and diseases