Huernia thuretii
| Light | Bright, filtered light; a little shade from scorching midday sun |
|---|---|
| Water | Moderate in warm growth; keep nearly dry and cool in winter |
| Soil | Very free-draining gritty mix (see Soil and potting mix) |
| Temperature | Keep above about 10 °C; USDA zones 9b–11 |
| Propagation | Stem cuttings (very easy); also seed |
| Toxicity | Generally regarded as non-toxic, though sap may irritate; keep away from curious pets |
Huernia thuretii is a low, clumping stapeliad succulent in the family Apocynaceae, grown for its charming star-shaped flowers. The blooms are pale and cream to yellowish, densely peppered with fine red or maroon spots, and divided into five broad triangular lobes surrounding a raised, glossy central ring known as the annulus — the doughnut-like feature that gives many Huernia their appeal. Like its relatives it is a member of the milkweed subfamily and a close cousin of the true carrion flowers.
Description
Huernia thuretii forms tight clusters of short, upright stems that branch freely from the base to build a low mound over time. The stems are grey-green, soft and fleshy, four- to six-angled, and lined along each ridge with rows of soft, non-spiny teeth rather than true spines. Individual stems are only a few centimetres tall, so a mature plant reads as a cushion of fingers rather than a tall specimen.
The flowers appear from the base of the stems, often several at once, in the warmer months. Each is a fleshy five-pointed star with broad, triangular lobes; the ground colour is pale — cream, ivory or soft yellow — and the surface is finely dotted with red to maroon speckles. At the centre sits the prominent, shining annulus, a fleshy raised ring that catches the light. As with other stapeliads the blooms may carry a faint, slightly unpleasant scent that attracts small flies as pollinators, though H. thuretii is generally far less pungent than the carrion-scented Stapelia.
Distribution and habitat
Huernia thuretii is native to southern Africa — the Cape Provinces of South Africa and Namibia — where it grows in dry, rocky habitat. Plants typically shelter among stones, in rock crevices, or beneath the light cover of low shrubs, rooting in gritty, sharply drained soils that dry out quickly after rain. This preference for a rocky, protected niche is a useful guide to how the plant likes to be grown in cultivation.
Cultivation
This is one of the easier and more forgiving stapeliads for the collector, and a good introduction to the group. Grow it in a very open, mostly mineral mix in a shallow pot, and give it bright, filtered light — enough for firm, well-coloured stems, but with some shade from the fiercest summer sun, which can scorch the soft growth. A little more shade than a typical globular cactus wants suits it well.
Water moderately while the plant is in active growth in the warmer months, always allowing the mix to dry between waterings, and keep it nearly dry and cool through winter to prevent rot. As with all stapeliads, the fleshy stems are prone to basal rot if kept cold and wet, so err on the dry side. See Watering and Repotting for general technique. Clumps are easily divided or refreshed, which also lets you re-root any stems that show signs of trouble.
Propagation
Propagation is very easy from stem cuttings. Detach a healthy stem or small cluster, let the cut surface dry and callus for a day or two, then set it on or just into a gritty, barely moist mix; roots form quickly in warm conditions. Because the plant clumps so readily, division of established clumps is often the simplest route. Seed is also possible where fresh seed is available, sown on a warm mineral surface, though cuttings are faster and keep the parent's characteristics. See Propagation — cuttings for a full walkthrough.
Common problems
- Basal and stem rot — the commonest cause of loss, almost always from cold, wet soil or a mix that drains too slowly; affected stems turn soft, translucent and brown. Remove them promptly and re-root clean growth.
- Sun scorch — the soft stems can bleach or develop tan patches under intense, unfiltered sun; give a little shade in the hottest months.
- Pests — mealybugs (white fluff tucked between the stem teeth and around the roots) are the usual pest; watch also for occasional aphids on developing buds. See Pests and diseases.
See also
- Huernia — the genus overview
- Stapeliads — the wider group of clumping Apocynaceae succulents
- Soil and potting mix · Watering · Propagation — cuttings · Propagation — offsets · Repotting · Pests and diseases