Stapelia variegata
| Light | Bright, filtered light to light shade; avoid harsh midday sun |
|---|---|
| Water | Regularly in the warm growing season once the mix dries; keep nearly dry in winter |
| Soil | Very free-draining, gritty succulent mix (see Soil and potting mix) |
| Temperature | Frost-tender; keep above about 5 °C, USDA zones 9b–11 |
| Propagation | Stem cuttings (easy) and seed |
| Toxicity | Generally regarded as non-toxic, though the flowers' carrion scent may attract flies |
Stapelia variegata, now correctly placed in its own genus as Orbea variegata, is a low-growing, clump-forming South African succulent famous for its fleshy, five-pointed, star-shaped flowers — yellow and heavily blotched with red-brown, giving rise to the common name starfish cactus. Despite that name it is not a cactus at all but a stapeliad in the milkweed family Apocynaceae, and its blooms give off a faint carrion odour that attracts flies as pollinators.
Description
Orbea variegata forms low mats of short, erect, four-angled green stems a few centimetres tall, the angles lined with soft, tooth-like tubercles rather than true spines. The stems are leafless and often flushed purplish or mottled when grown in strong light.
The flowers are the main attraction: broad, flat, five-lobed stars typically 5–8 cm across, pale yellow to greenish and boldly spotted and barred with maroon or red-brown. A raised, glossy ring (the annulus) sits at the centre around the intricate five-part crown typical of stapeliads. Each bloom lasts only a few days and emits a mild smell of rotting matter that draws flies, which pollinate the flower; you may occasionally find fly eggs deposited on open blooms. Fruit, when it forms, is a paired horn-like follicle releasing tufted, wind-borne seeds.
Distribution and habitat
The species is native to the winter-rainfall region of the Western Cape in South Africa, where it grows in rocky, well-drained ground, often tucked among stones or in the light shade of low shrubs. It is one of the most widely cultivated of all stapeliads and has been grown in Europe since the early days of succulent collecting, making it a familiar "pass-along" plant.
Cultivation
Orbea variegata is one of the easiest stapeliads to grow and a good introduction to the group. Plant it in a wide, shallow pot of very free-draining, gritty mix, as the clumps spread sideways and the shallow roots resent staying wet. Give it bright, filtered light or light shade; too little light produces weak, floppy growth, while a little sun stress brings out attractive mottling on the stems.
Water regularly through the warm growing season once the mix has dried, then reduce sharply and keep the plant nearly dry and frost-free over winter. The single greatest risk is overwatering, especially in cold weather, which causes soft black rot to spread through the stems. See Repotting for dividing crowded clumps.
Propagation
Propagation is easy and usually by stem cuttings. Detach a segment, let the cut end callus for several days to a week, then set it on or just into a dry, gritty mix and water only lightly until roots form. Clumps can also be lifted and divided. Seed is viable but less commonly used by hobbyists; sow on a warm, mineral surface and expect variable results. See Propagation — cuttings and Propagation — seed for full technique.
Common problems
- Stem rot — the classic stapeliad killer, almost always from overwatering, cold-and-wet conditions, or a poorly draining mix; affected stems turn soft and black and should be cut well back into healthy tissue.
- Etiolation — too little light gives pale, weak, elongated stems and few flowers.
- Pests — mealybugs (including root mealybugs) hide among the stem bases and roots; watch also for aphids on developing flower buds. See Pests and diseases.
- Flies and larvae — the carrion scent can attract flies that lay eggs on the flowers; harmless to the plant, but a reason some growers keep it away from living areas when in bloom.
See also
- Stapelia — the genus overview and its relatives
- Watering · Soil and potting mix · Propagation — cuttings · Repotting · Pests and diseases