Rhipsalis cereuscula
| Light | Bright, filtered light; protect from harsh direct sun (see Watering for seasonal notes) |
|---|---|
| Water | More generous than desert cacti; keep lightly moist in growth, easing off in winter, never waterlogged |
| Soil | Open, airy epiphytic mix with some organic matter (see Soil and potting mix) |
| Temperature | Warmth-loving; keep above about 10 °C, USDA zones 10–11 |
| Propagation | Stem cuttings (easy); also seed |
| Toxicity | Non-toxic to cats and dogs |
Rhipsalis cereuscula, commonly called the coral cactus or rice cactus, is a bushy, epiphytic jungle cactus from South America that builds up dense clusters of short, cylindrical, pencil-thin segments. As the plant matures the branches arch and trail, making it a favourite for hanging baskets and elevated pots. It belongs to the largely epiphytic genus Rhipsalis, and like its relatives it is spineless and adapted to life among the branches of humid forests rather than in the desert.
Description
Rhipsalis cereuscula forms a much-branched, shrubby plant of soft green stems. The main branches are slender and cylindrical, and at their tips they carry whorled clusters of very short, blunt segments — the feature that gives the species its rice-grain or coral appearance. Young growth stands more or less upright; with age and length the stems arch over and cascade, so an established plant becomes a tumbling mound of fine green segments.
The tiny areoles may bear a few soft, bristle-like hairs when young but the plant is essentially spineless and pleasant to handle. Small white to greenish-white flowers appear along and near the stem tips, usually in the cooler, shorter days of late winter and spring, and are followed by little translucent berries. The overall effect is delicate and fern-like rather than the stiff geometry most people expect from a cactus.
Distribution and habitat
The species is native to South America, where it grows across parts of Brazil and into neighbouring countries such as Argentina, Uruguay and Bolivia. It is an epiphyte (and sometimes a lithophyte), rooting in the leaf litter and mossy pockets that collect on tree branches and shaded rock in humid subtropical forest.
These habitats shape its needs in cultivation: dappled light beneath a canopy, steady humidity, regular moisture during the growing season and excellent air movement around the roots. It does not experience the baking sun or long droughts of a desert cactus, and it should not be grown as though it did.
Cultivation
Rhipsalis cereuscula is one of the more forgiving jungle cacti and an excellent houseplant. Grow it in bright but filtered light — an east-facing window, or a spot shaded from midday sun — as harsh direct sun scorches and reddens the stems, while deep shade leaves growth thin and sparse.
Unlike desert cacti, it appreciates being kept lightly moist through spring and summer: water when the top of the mix has begun to dry, and reduce watering in winter without letting the plant shrivel. Use an open, airy mix with some organic matter — many growers blend a standard potting mix with plenty of bark, perlite or pumice to mimic the loose, fast-draining material of an epiphyte's perch. It enjoys higher humidity than most cacti and rewards a warm, sheltered position. A hanging basket or raised pot shows off the trailing habit and keeps air moving around the stems. See Repotting for general technique.
Propagation
Propagation is very easy from stem cuttings. Detach a healthy segment or short length of stem, let the cut end callus for a day or so, then insert it into a moist, airy mix; cuttings root readily in warm, humid conditions. Fallen segments will often root where they land. The species can also be raised from seed, though cuttings are quicker and keep the plant true to the parent.
Common problems
- Overwatering and rot — although it likes more moisture than desert cacti, a soggy, airless mix will still rot the roots and base; the segments soften, discolour and drop.
- Shrivelling or wrinkled segments — usually a sign of underwatering or very low humidity, especially in a warm, dry room in winter.
- Sun scorch — too much direct sun bleaches or reddens the stems and can leave dry, damaged patches.
- Pests — mealybugs (white fluff tucked among the segments) and scale are the most common; watch also for spider mites in hot, dry air. See Pests and diseases.
See also
- Rhipsalis — the genus overview
- Soil and potting mix · Watering · Repotting
- Propagation — cuttings · Propagation — seed · Pests and diseases