Pseudorhipsalis
Pseudorhipsalis is a small genus of epiphytic cacti from the tropical forests of Central America, the Caribbean and northern South America. The plants grow as sprawling clumps of flattened, leaf-like stems that hang and trail from tree branches, and they are grown in cultivation as easy, forgiving hanging-basket plants prized for their many small flowers. Along with kin such as Rhipsalis, Epiphyllum and Disocactus, they belong to the group of "jungle cacti" that behave very differently from the desert species most people picture.
Description
Pseudorhipsalis are shrubby epiphytes with soft, spineless, strap-shaped or flattened stems that branch and cascade downward. The stems are usually thin, leaf-like and notched or toothed along the margins, superficially resembling a true Epiphyllum but generally narrower and more freely branching. Aerial roots sometimes form where a stem touches bark or soil, helping the plant anchor to its host.
The flowers are small relative to the showy Epiphyllum blooms — typically a few centimetres or less across — but are produced in generous numbers along the stem margins. Colours range from creamy white and greenish to soft yellow, salmon and pink depending on the species. Flowering is followed by small, rounded, translucent or pinkish berries, much like those of related jungle cacti.
Distribution
The genus is centred on the humid lowland and montane forests of Central America, chiefly Costa Rica and Panama, extending into the Caribbean (with P. alata in Jamaica) and parts of northern South America. In habitat the plants grow as epiphytes perched on tree trunks and branches, rooted in pockets of leaf litter and moss rather than in the ground, in bright but dappled shade with high humidity and regular rainfall.
Notable species
- Pseudorhipsalis ramulosa — the most widespread and commonly grown of these plants, with slender flattened stems that often flush red in bright light and tiny cream to pinkish flowers followed by pale berries; recent molecular work has segregated it into its own monotypic genus Kimnachia (as Kimnachia ramulosa), though it is still almost always sold under the Pseudorhipsalis name.
- Pseudorhipsalis amazonica — a robust species with broader stems and comparatively large, showy pink to purplish flowers; sometimes still traded under the name Disocactus.
- Pseudorhipsalis himantoclada — noted for its long, strongly toothed, hanging stems.
Several species have been shuffled back and forth between Pseudorhipsalis, Disocactus, Kimnachia and other genera over the years, so names in the trade can be inconsistent — the synonym Disocactus (in part) reflects this history.
Cultivation
As tropical epiphytes, Pseudorhipsalis want conditions closer to those of an orchid than a desert cactus, and they make undemanding houseplants for a bright spot out of harsh sun. Grow them in bright, indirect light or gentle morning sun; too much fierce midday sun scorches the stems, while too little produces weak, sparse growth (though modest sun stress gives the attractive reddish tint many growers like).
Plant in a loose, airy, well-drained medium rich in organic matter — an epiphyte or orchid-style mix with bark, coir and perlite suits them well. Unlike desert cacti they should not be kept bone dry: water regularly through the growing season, letting the top of the mix dry slightly between waterings, and ease off in winter without allowing the stems to shrivel. They appreciate warmth, high humidity and protection from frost, and are ideally suited to hanging baskets where the trailing stems can spill freely. A cooler, drier spell in winter helps trigger the spring flush of flowers. Feed lightly during active growth and repot when a basket becomes crowded.
Propagation
These cacti are among the easiest of all to propagate from stem cuttings. Remove a healthy stem segment, let the cut end callus for a day or two, then set it in a moist, airy mix; it will usually root quickly and begin trailing within a season. Larger clumps can also be divided at repotting time. Seed is possible from the small berries but is slower and mainly of interest to specialists — see Propagation — seed.
Common problems
- Stem rot — the usual result of a soggy, airless mix or standing water in the basket; provide sharp drainage and let the surface dry between waterings.
- Shrivelling — thin, wrinkled stems signal under-watering or very low humidity, as these forest plants are less drought-tolerant than desert cacti.
- Scorch — pale or bleached patches where the plant is exposed to direct midday sun.
- Pests — mealybugs and scale can lodge along the stems; see Pests and diseases.
See also
- Rhipsalis · Epiphyllum · Disocactus — related jungle cacti
- Soil and potting mix · Watering · Propagation — cuttings · Repotting