Mammillaria mystax
| Light | Bright light; a little shade from the harshest afternoon sun |
|---|---|
| Water | Sparingly; let the mix dry fully between waterings, keep dry in winter |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; roughly USDA zones 9b–11 |
| Propagation | Seed; offsets from older clustering plants |
| Toxicity | Non-toxic to cats and dogs |
Mammillaria mystax is a robust, globular to shortly columnar cactus from central and southern Mexico, valued for its striking contrast of dark green tubercles, pale woolly axils and long, twisted central spines. Older plants may remain solitary or slowly form small clusters, and in season they crown themselves with a neat ring of deep purple-pink flowers. It is one of the more architectural species in the large genus Mammillaria, and a rewarding, forgiving plant for the intermediate grower.
Description
Mammillaria mystax forms a firm, rounded to slightly elongated body, typically deep green to grey-green, that can reach a good size for the genus over many years. The surface is built from stout, pyramidal, four- to six-angled tubercles arranged in spirals; the sunken axils between them fill with white wool and, in mature plants, fine bristles.
Each areole carries a spreading crown of shorter radial spines and one to several long central spines. These centrals are the plant's signature feature — dark-tipped and often purplish, and often noticeably curved or twisted, standing out well beyond the body. The specific epithet mystax (from the Greek for "moustache") nods to this whiskered look.
Flowers appear in a ring around the crown, usually in spring, and are a rich rose-purple to purple-pink, small but numerous and set off handsomely against the wool. As with most Mammillaria, successful flowering is followed by slender, club-shaped red fruits that push out from the axils weeks or months later.
Distribution and habitat
The species is native to central and southern Mexico, where it grows on rocky slopes, ledges and among scrub in seasonally dry country. Plants root in coarse, well-drained ground and endure a long dry season followed by summer rains, a rhythm worth keeping in mind when watering in cultivation. It is a widespread and variable species, and growers may encounter several regional forms under this name.
Cultivation
Mammillaria mystax is one of the easier globular cacti to please, provided its roots are never left wet. Grow it in a gritty, mostly mineral mix in a pot that drains freely, and give it bright light — full sun in temperate climates helps develop strong spines and encourages the best flowering, with only a little shading needed where afternoon sun is fierce.
Water thoroughly during the warm growing season once the mix has dried out, then let it dry again before the next drink. Through winter, keep the plant cool and essentially dry; a proper cold, dry rest is what triggers the spring ring of flowers and greatly reduces the risk of rot. See Watering and Repotting for general technique.
Propagation
Seed is the most reliable method and produces the truest plants; sow onto a warm, gritty surface kept lightly humid until germination, as described in Propagation — seed. Older specimens that have branched into a cluster can also be increased by removing rooted offsets and letting the cut surfaces callus before potting — see Propagation — offsets. Because many plants stay solitary for a long time, seed remains the mainstay for this species.
Common problems
- Rot — the usual killer, caused by overwatering, a mix that holds moisture, or watering during the cold rest. The body softens and discolours from the base or crown.
- Etiolation — too little light makes growth pale, soft and elongated, and spoils the compact shape and spine strength.
- Pests — mealybugs lodge as white fluff in the wool of the axils, and root mealybugs can hide in the rootball; red spider mites may bronze the skin in hot, dry, still air. See Pests and diseases.
See also
- Mammillaria — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — seed · Propagation — offsets · Pests and diseases