Aztekium valdezii
| Light | Bright but filtered light; protect from harsh direct sun |
|---|---|
| Water | Very sparingly; allow to dry completely, near-dry through winter |
| Soil | Extremely free-draining mineral mix, often with added limestone grit (see Soil and potting mix) |
| Temperature | Keep frost-free; USDA zones 9b–11 |
| Propagation | Seed; frequently grafted as seedlings to speed growth |
| Toxicity | Not known to be toxic to cats or dogs |
Aztekium valdezii is a rare, very small cactus in the genus Aztekium, described only in 2013 from a single restricted, cliff-side population in northeastern Mexico. It is distinguished by its unusually low rib count — only about five ribs, and lacking the secondary "false" ribs typical of the genus — together with comparatively large, magenta-pink flowers, and it has become one of the most coveted — and heavily protected — of all miniature collector cacti.
Description
Aztekium valdezii is a diminutive, slow-growing cactus that stays only a few centimetres across. Like its relatives in Aztekium it has a firm, greyish-green body divided into ribs, but where those relatives carry many ribs — often overlaid with additional secondary "false" ribs — A. valdezii has only about five, and lacks that false ribbing. This gives the plant a clean, boldly sculptured outline that looks star-shaped when viewed from above, quite distinct from the finely folded, almost brain-like surface of the closely related Aztekium ritteri. As in the genus, any spines are small, soft and papery, borne mainly on the upper part of the stem, so the sculptured body itself is the main ornament.
The flowers are relatively large for so small a plant, funnel-shaped and magenta-pink — white in the centre and grading to bright magenta towards the margins — opening from the woolly crown. Along with the low rib count, differences in the flowers help separate the species from its relatives.
Distribution and habitat
The species is known from a very restricted area in the state of Nuevo León in northeastern Mexico, where it grows on steep, near-vertical rock faces. Plants root in cracks and crevices of the cliff, anchored in minimal mineral substrate and exposed to bright light but sheltered from prolonged soaking. This cliff-dwelling habit, combined with an extremely small known range, makes the wild population highly vulnerable.
Because it is so rare and localised, A. valdezii has been a target of illegal collection since its discovery, and — like the entire cactus family — it falls under CITES protection. Wild plants must be left in place; only nursery-propagated, seed-grown material should ever be bought or traded.
Cultivation
Aztekium valdezii is regarded as a challenging plant, best suited to experienced growers. It demands an exceptionally free-draining, mostly mineral mix — many growers add limestone grit to reflect the calcareous rock of its habitat — in a small pot that dries quickly. Give it bright light with some protection from the fiercest midday sun, and water only sparingly once the substrate has dried completely. Keep it nearly dry and cool through winter to avoid rot, which is the usual cause of death.
The species is famously slow on its own roots. To build up young plants more quickly, growers very commonly graft seedlings onto a vigorous rootstock, growing them on either permanently grafted or later re-rooted onto their own roots. See Watering and Repotting for general technique.
Propagation
Seed is the primary means of propagation, and responsible seed-raising is the main way this rare species is kept in cultivation without pressure on the wild population. The seeds are tiny and slow, and seedlings are delicate; many growers graft them at an early stage to improve survival and growth rate. Offsetting is limited, so vegetative increase from the plant itself is uncommon. See Propagation — seed for a full walkthrough.
Common problems
- Rot — by far the greatest risk; overwatering, a slow-draining mix or winter moisture will cause the body to soften and collapse.
- Loss on own roots — ungrafted plants grow extremely slowly and are easily set back, which is why grafting is so widespread.
- Pests — mealybugs can hide among the ribs and in the crown wool; root mealybugs and spider mites are also possible.
Legal status
As a member of the family Cactaceae, Aztekium valdezii is covered by CITES. The family as a whole is listed on Appendix II, which regulates international trade, while the closely related Aztekium ritteri — with which A. valdezii has been treated as synonymous — is on the stricter Appendix I; the exact listing of A. valdezii itself has been the subject of CITES review. Given its tiny natural range and desirability to collectors, wild plants are especially threatened by poaching. Ownership and trade of legitimately nursery-propagated, seed-grown specimens is legal in most places, but material collected from habitat is not; always buy from a reputable source that can document artificial propagation.
See also
- Aztekium — the genus overview
- Aztekium ritteri — the long-known relative, with more numerous ribs and the genus's characteristic false ribbing
- Grafting · Soil and potting mix · Watering · Propagation — seed · Pests and diseases