Mammillaria surculosa
| Light | Bright light with some protection from the harshest afternoon sun |
|---|---|
| Water | Moderately in growth; allow to dry between waterings, dry rest in winter |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; roughly USDA zones 9b–11 |
| Propagation | Offsets (primary); seed |
| Toxicity | Non-toxic to cats and dogs |
Mammillaria surculosa is a small, freely clustering cactus from northeastern Mexico that forms low, spreading mats of soft green stems. Each head is covered in slender, elongated tubercles tipped with a single yellow to amber hooked central spine surrounded by finer radials, and mature clumps produce a generous succession of relatively large, fragrant yellow flowers. It was long known in the trade under the name Dolichothele surculosa, a reflection of its notably long, finger-like tubercles.
Description
Mammillaria surculosa makes small individual heads only a few centimetres across, but it offsets prolifically to build broad, low cushions over time. The stems are soft-bodied and fresh green, distinguished by their long, cylindrical tubercles that give the plant a loose, slightly shaggy look compared with the tightly packed tubercles of many other Mammillaria.
Each tubercle carries a small cluster of thin, pale radial spines and, at the centre, a single (occasionally paired) golden-yellow to amber central spine that hooks at the tip. Like others of the Dolichothele group, it lacks the milky sap found in some other mammillarias. The flowers are large for the plant's size, funnel-shaped and clear lemon-yellow, and — unusually among cacti — carry a light, pleasant fragrance. They open over a long spring-to-summer season and are followed by small greenish to reddish fruits.
Distribution and habitat
The species is native to northeastern Mexico, in the states of Tamaulipas and San Luis Potosí and the surrounding region, where it grows in scrub and rocky ground, often nestled among grasses, leaf litter and low shrubs that give it dappled shade and a bit of extra moisture at the roots. Although common and easy in cultivation, in the wild it is restricted to a few isolated patches at roughly 950–1,200 m and is assessed as Endangered on the IUCN Red List.
Cultivation
Mammillaria surculosa is an easy, forgiving grower and a good choice for beginners. Its soft stems appreciate a little more water than the toughest desert cacti, but the fundamentals of the genus still apply: a very free-draining, largely mineral mix, bright light with a touch of shade from the fiercest afternoon sun, and thorough watering once the mix has dried out during the growing season. Keep it dry and cool through winter to prevent rot and to encourage a strong flush of flowers.
Because it clusters so readily, plants are usually grown in a wide, shallow pot that gives the mat room to spread. See Watering and Repotting for general technique.
Propagation
The simplest method is to detach rooted or nearly rooted offsets from the edge of an established clump, let the cut surface callus for a few days, and pot them into a gritty mix. The species also grows readily from seed, which is the best route if you want a large number of plants or fresh genetic variety.
Common problems
- Rot — the usual cause of loss, brought on by a soggy mix or overwatering, especially in cool weather; the soft stems discolour and collapse.
- Etiolation — too little light makes the heads stretch, pale and lose their compact form.
- Pests — mealybugs (white fluff among the tubercles, and on the roots) and red spider mites are the most common; see Pests and diseases.
See also
- Mammillaria — the genus overview
- Soil and potting mix · Watering · Propagation — offsets · Propagation — seed · Repotting