Pachycereus schottii f. monstrosus
Pachycereus schottii f. monstrosus, better known as the totem-pole cactus, is a smooth, spineless, knobbly monstrose form of Pachycereus schottii (the senita cactus) that is widely grown as an easy-going landscape novelty. Where the normal species is a ribbed, spiny columnar cactus, this cultivated form produces soft grey-green columns with an irregular, lumpy surface and no spines at all, so that a mature clump looks like a cluster of weathered carved posts.
Care follows the parent species; see Pachycereus for full cultivation notes.
Description
The totem-pole cactus grows as an upright, branching column that can eventually reach a considerable height in the ground, though it is slow and stays manageable for many years. The stems are pale grey-green and, in place of the parent's neat vertical ribs and areoles, they are covered in rounded, irregular bumps and folds that give the plant its characteristic knobbly, "melted" look. It is essentially spineless, which makes it pleasant to handle and popular near paths and seating areas.
Because it is a monstrose sport, growth is not perfectly symmetrical or predictable: each column develops its own quirks, and the surface texture varies from smooth swellings to tighter, more congested clusters. Flowering is uncommon and generally incidental in cultivation; the plant is grown almost entirely for its curious form rather than its flowers.
Cultivation
Cultivation is as for the parent species, Pachycereus schottii — see that page for details. In short, give it bright light to full sun, a very free-draining, mostly mineral mix, and water only when the soil has dried out, tapering off in winter. It is happiest in warm, frost-free conditions and should be protected from hard freezes.
A few notes specific to the monstrose form:
- Like many spineless, soft-bodied monstrose cacti, it can scorch if moved abruptly into full desert sun after being grown in shade, so acclimatise it gradually.
- The knobbly surface holds moisture and debris in its crevices, so avoid leaving it wet and cold, which invites rot.
- It roots and establishes readily, making it a forgiving plant for beginners and a common sight in low-water and xeriscape gardens.
Propagation
The totem-pole cactus is propagated vegetatively from stem cuttings, which keeps the monstrose trait true — seed-grown plants would revert to the normal spiny species. Take a length of stem, let the cut end callus for several days to a couple of weeks in a dry, shaded spot, then set it in a gritty, barely-moist mix until roots form. This is the standard way the plant is bulked up in the nursery trade.
See also
- Pachycereus — the genus overview and parent species
- Propagation — cuttings · Soil and potting mix · Watering · Repotting · Pests and diseases