Myrtillocactus geometrizans 'Fukurokuryuzinboku'
Myrtillocactus geometrizans 'Fukurokuryuzinboku, affectionately known as the booby cactus (or boob cactus), is a knobbly, aberrant cultivar of the blue candle cactus Myrtillocactus geometrizans. Instead of the parent's clean, geometric ribbed columns, this form grows in irregular, lumpy stems studded with smooth rounded protuberances — the source of its cheeky common name and its popularity as a novelty collector's plant.
Description
Where typical Myrtillocactus geometrizans produces slender, blue-grey columns with crisp vertical ribs, 'Fukurokuryuzinboku' is a monstrose form in which the normal ribbing breaks down. The stems swell into knobbly, tuberculate mounds covered in soft-looking, hemispherical bumps, giving the plant its distinctive knobbly silhouette. Areoles and short spines are scattered irregularly over the surface rather than lined up along ribs.
The waxy skin keeps the same handsome blue-green to grey-green colouring as the species, and the plant branches and clumps with age into a sculptural, many-headed specimen. Growth is generally slower and more compact than the plain species, and the degree of "bobbing" varies from stem to stem — a hallmark of monstrose cacti.
Like the species, this cultivar can flower and even fruit on mature plants, though it is grown almost entirely for its curious form rather than its bloom.
Cultivation
Care is the same as for the parent species, Myrtillocactus geometrizans. Give it bright light and a very free-draining, mostly mineral mix, water thoroughly once the soil has dried out, and keep it dry and frost-free through winter. It is a forgiving grower by cactus standards.
A few notes specific to the monstrose form:
- Light matters for form. Strong light keeps the bumps tight, plump and well-coloured; in dim conditions the plant tends to etiolate, producing pale, stretched growth.
- Watch for reversion. Monstrose stems sometimes throw out sections of normal, ribbed columnar growth. If you want to preserve the knobbly look, these reverted shoots can be pruned away.
- Grafting. Like many novelty and slow monstrose cacti, 'Fukurokuryuzinboku' is often grafted onto a vigorous columnar rootstock to speed it up and show off the heads, though it grows perfectly well on its own roots too.
For general technique see Watering, Repotting and Pests and diseases.
Propagation
The cultivar is maintained vegetatively so that the monstrose trait is preserved. Stem sections root readily as cuttings once the cut surface has callused. As the plant branches and clumps, individual heads or offsets can likewise be removed and rooted. Grafting is also widely used. Seed is not used to reproduce the cultivar, as seedlings would not come true to the monstrose form.
See also
- Myrtillocactus — the parent genus and species
- Grafting · Propagation - cuttings · Propagation - offsets · Soil and potting mix · Watering