Gymnocalycium mihanovichii f. variegata
Gymnocalycium mihanovichii f. variegata is a group of colourful, chlorophyll-variegated selections of the Gymnocalycium chin cactus, in which the body is marbled with irregular sectors of green and warm reds, oranges, pinks or yellows. Unlike the familiar moon cactus — a fully chlorophyll-free red or yellow scion that must be grafted onto a green rootstock to survive — these variegated forms keep enough green tissue to photosynthesise, so many of them can be grown on their own roots.
As a cultivar group its care follows that of the parent species, Gymnocalycium mihanovichii; see that page and the notes below for the differences that variegation introduces.
Description
Variegated G. mihanovichii shares the small, squat, ribbed body of the species — a flattened globe a few centimetres across, with broad ribs bearing the transverse "chin"-like bulges beneath each areole that give the group its common name. What sets these plants apart is the pigmentation: patches of the body lack normal green chlorophyll and instead show the underlying carotenoid and betalain pigments, producing marbled sectors of red, pink, orange or yellow against green.
The distribution of colour is unstable and unpredictable. A single plant may carry anything from a few coloured flecks to broad coloured wedges, and the pattern can shift as the plant grows and offsets. Selections marketed under names such as Nishiki (a Japanese term for variegated plants) are chosen for attractive, stable marbling. Small pinkish flowers may appear from the areoles near the crown, as in the parent species.
Cultivation
Grow variegated G. mihanovichii as for the parent species, Gymnocalycium mihanovichii: a free-draining, mostly mineral mix, careful watering with a full dry-down between drinks, and a dry, cool winter rest. A few points deserve extra attention because of the variegation:
- Less chlorophyll means slower growth. Coloured sectors contribute little or no energy, so variegated plants are generally weaker and slower than plain green ones. Feed lightly and be patient.
- Light is a balancing act. Good bright light keeps the colours vivid and the body compact, but the reduced green tissue and pale sectors scorch more easily than a fully green plant. Give bright light with shade from harsh direct summer sun.
- Highly coloured plants may need grafting. Selections that are almost entirely red or yellow have too little chlorophyll to sustain themselves and are effectively moon cacti — these are grafted onto a vigorous rootstock such as Hylocereus or Myrtillocactus. Plants that retain substantial green can usually be grown on their own roots.
- Watch for rot. As with all Gymnocalycium, overwatering and cold, wet compost are the main killers; keep the plant on the dry side, especially in winter. See Repotting for general technique.
See also
- Gymnocalycium mihanovichii — the parent species
- Gymnocalycium — the genus overview
- Grafting · Soil and potting mix · Watering · Propagation — offsets