Eriosyce odieri
| Light | Bright light with a little shade from harsh afternoon sun |
|---|---|
| Water | Very sparingly; allow to dry out completely between waterings, dry rest in winter |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; frost-free, roughly USDA zones 9b–11 |
| Propagation | Seed; grafting to speed slow seedlings |
| Toxicity | Non-toxic to cats and dogs |
Eriosyce odieri is a small, flattened, geophytic cactus from the arid coastal deserts of northern Chile, prized among collectors as a true miniature. Its low, disc-like body sits close to the soil over a stout taproot, is patterned in dusky greens, browns and purples, and carries tiny, appressed comb-like spines; despite the plant's modest size it produces relatively large, showy flowers in pale tones of white, yellow, pink and soft orange. It is often still sold under its older names Neochilenia odieri and Thelocephala odieri.
Description
Eriosyce odieri is a dwarf species that usually stays solitary and rarely exceeds a few centimetres across. The body is flattened to shortly globular and, in habitat, retracts down toward soil level in drought, so that little more than the patterned crown shows among the surrounding grit. Beneath the surface it anchors itself with a thickened, turnip-like taproot — the geophytic habit that helps it survive long dry periods.
The skin is firm and often beautifully marbled in olive, grey-green, reddish-brown and purplish tones, giving well-grown plants an almost stone-like camouflage. The spines are small, short and comb-like (pectinate), lying close against the body rather than projecting outward, so the plant feels far less fierce than most cacti; older plants are often nearly spineless. Relative to the size of the body, the flowers are fairly large: funnel-shaped blooms in pale tones — whitish, yellow, pink or soft orange — open from the woolly crown, mainly in the warmer months.
Distribution and habitat
The species is native to the coastal deserts of the Atacama region of northern Chile, one of the driest environments on Earth. There it grows at low elevation in open, stony ground, drawing much of its moisture from coastal fog rather than rainfall. The retractile, taproot-anchored body and camouflaged skin are adaptations to this exposed, sun-baked and drought-prone habitat.
Like all cacti, Eriosyce species are listed under CITES Appendix II, and wild populations of these small Chilean cacti can be vulnerable to over-collection and habitat disturbance. Nursery-propagated, seed-grown plants are the responsible source; plants should never be taken from the wild.
Cultivation
Eriosyce odieri is a rewarding miniature but demands care with water, as its swollen taproot rots easily if kept damp. Grow it in a very gritty, mostly mineral mix in a deep pot that accommodates the taproot, and give it bright light with only light shading from the most intense summer sun. Water thoroughly but infrequently during the growing season, always letting the mix dry out completely first, and keep the plant dry and cool through winter to prevent rot and encourage flowering. See Watering and Repotting for general technique.
Because the species is slow-growing, some growers graft young seedlings onto a vigorous rootstock to build them up more quickly, later returning selected plants to their own roots. On their own roots the plants stay compact and keep their natural, characterful appearance.
Propagation
Seed is the usual and most reliable method. Sow onto a warm, gritty surface kept humid until germination, then grow the seedlings on slowly and carefully, as they are small and sensitive to overwatering. The species rarely offsets, so vegetative propagation is uncommon apart from grafting. See Propagation — seed for a full walkthrough.
Common problems
- Rot — the most common cause of loss; almost always from overwatering, a slow-draining mix, or moisture around the taproot. Plants soften and discolour from the base.
- Etiolation — too little light makes the flattened body dome upward and lose its tight, patterned symmetry.
- 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
- Eriosyce — the genus overview
- Grafting · Soil and potting mix · Watering · Repotting · Propagation — seed · Pests and diseases