Aloinopsis
Aloinopsis is a small genus of clump-forming, tuberous-rooted mesembs (family Aizoaceae) native to the drier interior of South Africa. Each plant forms a low rosette of thick, spoon-shaped leaves whose upper surfaces are studded with raised, warty tubercles, and sits atop a stout, carrot-like taproot that stores water and nutrients through long dry spells. The genus is closely allied to — and often confused with — Nananthus and Titanopsis, with which it shares the same tubercled, pebble-like look.
Description
Aloinopsis plants are compact and slow-growing, rarely more than a few centimetres tall above ground but anchored by a disproportionately large tuberous root. The leaves are fleshy, keeled and roughly spoon- or club-shaped, arranged in small opposite pairs that build up into tight rosettes or low mounds over time. Their surfaces are typically grey-green, blue-green or bronzed, and are covered in pale, raised tubercles that give the foliage a rough, encrusted texture — an adaptation that helps the plants blend into the gritty ground they grow among.
Like other mesembs, Aloinopsis produces relatively large, daisy-like flowers on short stalks, usually in the cooler months of autumn and winter. The blooms are often yellow, sometimes flushed with salmon, orange or reddish tones and fine central stripes, and tend to open in the afternoon and close again toward evening.
Distribution
The genus is confined to South Africa, chiefly across the semi-arid Karoo and neighbouring dry regions of the Northern, Eastern and Western Cape and the Free State. Plants grow in open, exposed positions in stony, mineral-poor soils, where the swollen root is drawn down into the ground and the tubercled rosette lies flush with the surrounding grit and rock — camouflage against grazing and the harsh sun.
Notable species
- Aloinopsis schooneesii — perhaps the most widely grown, forming neat clusters of tubercled leaves and cheerful yellow winter flowers.
- Aloinopsis luckhoffii — noted for strongly warty, bronzed leaf tips and comparatively large blooms.
- Aloinopsis rosulata — a tidy rosette-former from stony flats.
- Aloinopsis spathulata — with broad, spoon-shaped leaves and pink-to-salmon flowers, sometimes segregated into the related genus Nananthus.
- Aloinopsis malherbei — an attractive species with pale, densely tuberculate leaves.
Species boundaries in this group are unsettled, and several plants sold as Aloinopsis are treated by some authorities under Nananthus or Deilanthe.
Cultivation
Aloinopsis is a rewarding subject for growers who enjoy winter-flowering succulents, and it is more forgiving of cold than many mesembs. Grow it in a very free-draining, mostly mineral mix in a deep pot that accommodates the long taproot, and give it the brightest position you can — poor light quickly makes the rosettes stretch and lose their compact, encrusted character.
These are winter growers: water is best given in autumn, winter and spring while the plants are in active growth and flower, then reduced sharply through the heat of summer, when they take a partial rest. Always allow the soil to dry between waterings, and err on the dry side, since the tuberous root is prone to rot if kept wet and cold at the same time. Many growers keep the crown of the root at or just below soil level for a natural look, though raising it slightly above the surface (as with a caudex) is popular for display. See Watering and Repotting for general technique.
Being high-altitude Karoo plants, most Aloinopsis tolerate light frost if kept dry, but they should be protected from prolonged freezing and from wet cold.
Propagation
Seed is the usual method, sown on a gritty, mineral surface kept lightly moist and warm; germination is generally reliable and seedlings develop their tuberous roots early. Established clumps can also be divided, and older plants sometimes offset, allowing sections with their own roots to be separated at repotting. See Propagation — seed and Propagation — offsets for details.
Common problems
- Root and stem rot — the most frequent cause of loss, almost always from overwatering, a poorly draining mix, or water sitting on the plant during cold weather.
- Etiolation — too little light makes the rosettes elongate, pale and lose their tight, tubercled form.
- Pests — mealybugs (including root mealybugs on the tuber) and, in dry conditions, spider mites are the usual offenders; check the root ball at repotting. See Pests and diseases.
See also
- Nananthus — closely related, often confused genus
- Titanopsis — another tubercled Karoo mesemb
- Aizoaceae — the mesemb family overview
- Soil and potting mix · Watering · Repotting · Propagation — seed · Propagation — offsets