Coryphantha maiz-tablasensis
| Light | Bright light; a little shade from harsh summer afternoon sun |
|---|---|
| Water | Sparingly; allow to dry fully between waterings, keep dry in winter |
| Soil | Very free-draining, gritty mineral mix (see Soil and potting mix) |
| Temperature | Keep dry and near frost-free; tolerates brief light frost (to about −4 °C) only if kept bone-dry (roughly USDA zone 9b) |
| Propagation | Seed (primary); older plants cluster and offsets can occasionally be divided |
| Toxicity | Not reported toxic to cats or dogs; no species-specific data |
Coryphantha maiz-tablasensis is a small, tuberous-rooted cactus endemic to the state of San Luis Potosí in central Mexico, prized by collectors as a rare and threatened miniature. Its body is built from plump, rounded to conical tubercles arranged in neat spirals, and it is one of the more distinctive dwarf members of the genus Coryphantha. The epithet maiz-tablasensis is geographic rather than descriptive, drawn from its type region — the municipality of Ciudad del Maíz and the dry lagoon (lake-flat) of Las Tablas in San Luis Potosí.
Description
Coryphantha maiz-tablasensis is a small plant, solitary when young but in time clustering into low groups, whose visible body sits close to the ground above a thickened, beet-like taproot. The stem is composed of firm, rounded to conical tubercles arranged in spirals. As in other Coryphantha, each tubercle carries a groove on its upper surface, and the woolly areoles bear only modest clusters of short spines — typically a handful of white, dark-tipped radials and no central spine — rather than a dense armour.
The swollen root stores water and carbohydrate, allowing the plant to shrink back into the soil and ride out drought — a survival strategy shared with many miniature Mexican cacti. Flowers appear from near the growing point in the warmer months; they are broadly funnel-shaped and cream-white, up to about 4–6 cm across, opening in bright conditions.
Distribution and habitat
The species is native to a small area of San Luis Potosí in central Mexico, where it grows on flat, gypsum-rich ground — old lake- and mud-flats and gypsum soils carrying sparse grass and only scattered trees or shrubs. Plants sit low against the pale substrate, with the water-storing root anchored well below the surface. It is known from only a few sites; as with many narrowly distributed Mexican cacti, wild populations are limited and vulnerable to habitat loss (notably agricultural conversion) and over-collection, so nursery-propagated plants are the responsible choice for the collection. Like the whole cactus family it is covered by CITES Appendix II.
Cultivation
Because of its swollen root, C. maiz-tablasensis is more than usually sensitive to excess moisture, and rot at the root or neck is the main risk in cultivation. Grow it in a deep pot to accommodate the root, in a very free-draining, largely mineral mix, and give it bright light with only light shade from the fiercest afternoon sun. Water thoroughly once the soil has dried right through during active growth, then let it dry again; keep the plant dry and cool over winter to firm it up and encourage flowering. See Watering and Repotting for general technique.
It is a slow grower and, being uncommon, is usually seen in the collections of specialist growers rather than in general trade.
Propagation
Seed is the standard and most reliable method. Sow onto a warm, gritty, mineral surface kept humid until germination, then grow the seedlings on hard and unhurried. Established plants tend to cluster with age, so offsets can sometimes be separated, though seed remains the usual route to good numbers; see offsets. Grafting is sometimes used to bring on slow seedlings more quickly. See Propagation — seed for a full walkthrough.
Common problems
- Rot — by far the commonest cause of loss, usually from overwatering, a slow-draining mix, or moisture sitting around the swollen root and neck.
- Etiolation — too little light makes the tubercles soft and elongated, spoiling the compact form.
- Pests — root mealybugs on the root, ordinary mealybugs in the tubercle grooves, and red spider mites are the usual offenders; see Pests and diseases.
See also
- Coryphantha — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — seed · Pests and diseases