Austrocylindropuntia subulata
| Light | Full sun to bright light; tolerates more sun than most opuntioids |
|---|---|
| Water | Regular in the growing season, letting the mix dry between waterings; keep dry in winter |
| Soil | Free-draining mineral-rich mix (see Soil and potting mix) |
| Temperature | Best above freezing; briefly tolerates light frost when dry; USDA zones 9b–11 |
| Propagation | Stem cuttings (very easy); also seed |
| Toxicity | Not considered toxic, but the spines and glochids cause mechanical injury |
Austrocylindropuntia subulata is a fast-growing, shrubby to tree-like columnar cactus from the Andes of South America, best known by the common name Eve's needle. It belongs to the opuntioid genus Austrocylindropuntia and is easily recognised by its long, cylindrical green stems, its stout spines and — most distinctively — the long, persistent, awl-shaped (subulate) leaves that give the species both its botanical and common names.
Description
Austrocylindropuntia subulata forms an erect, freely branching plant that can build up into a large shrub or small tree well over head height in the ground, though it stays much smaller in a pot. The cylindrical stems are bright to greyish green, several centimetres thick, and marked with low, spiralling tubercles rather than the flat pads of a true Opuntia.
Its most characteristic feature is the leaves: unlike most cacti, which reduce their leaves to nothing, this species produces long, narrow, fleshy, awl-shaped leaves that persist on the stems for a long time before dropping. From the areoles emerge one to a few stout, pale, needle-like spines, together with tufts of fine, barbed glochids that detach easily and irritate the skin. Flowers, when they appear on mature plants, are reddish to orange and are followed by elongated, sometimes proliferating fruits.
Distribution and habitat
The species is native to the Andes, centred on Peru, where it grows on dry slopes and in scrub at moderate to high elevations. It is vigorous and adaptable, and has become widely naturalised in other dry, frost-free regions of the world — around the Mediterranean, in parts of Australia and South Africa, and elsewhere — where it is sometimes grown as a living fence. In some of these regions it is regarded as a weed because broken segments root so readily.
Cultivation
Austrocylindropuntia subulata is one of the easiest cacti to grow and is a good beginner's plant. Give it a free-draining mineral mix and the brightest position you can offer; in strong light the stems stay compact and the leaves are held well, while in shade the plant etiolates and grows soft and lax. Water fairly generously through the warm growing season, always letting the mix dry between waterings, then keep it dry and cool over winter. See Watering and Repotting for general technique.
Because it grows so quickly, it may need staking or regular pruning to keep a tidy shape, and it can rapidly outgrow a small pot. The vigorous, undemanding stems are also sometimes used as a rootstock for grafting other cacti, though sturdier columnar stocks are more common.
Handle the plant with care: the glochids are easily dislodged and lodge painfully in the skin, so use thick gloves or a folded strip of newspaper when repotting or taking cuttings.
Propagation
Propagation could hardly be simpler. A cut stem segment, left to callus for a few days in a dry, shaded spot, roots quickly when set in barely moist mineral mix — this is the standard method and the reason the species spreads so freely where it has naturalised. See Propagation — cuttings. Seed is also viable but is rarely needed given how readily cuttings strike; for that route see Propagation — seed.
Cultivars
A monstrose form, sometimes sold as Austrocylindropuntia subulata f. monstrosa or under the name "Cristata", is popular in the trade. It grows as a dense, congested cluster of short, irregular, tuberculate stems with reduced leaves, forming a distinctive knobbly column quite unlike the wild plant. Care for it is as for the species, though these slower monstrose forms appreciate a little extra caution with watering.
Common problems
- Etiolation — the commonest issue; too little light makes stems thin, pale and weak, and the plant leans or topples.
- Rot — from a waterlogged mix or overwatering in cold weather; stems soften and discolour from the base.
- Pests — mealybugs (white fluff in the areoles) and scale can settle on the stems; red spider mites are less common outdoors. See Pests and diseases.
- Glochid irritation — not a plant problem but a grower one; the barbed glochids are the main reason to handle this species carefully.
See also
- Austrocylindropuntia — the genus overview
- Opuntia — the related flat-padded opuntioids
- Grafting · Soil and potting mix · Watering · Propagation — cuttings · Pests and diseases