Conophytum
Conophytum is a genus of dwarf, clump-forming succulents in the ice-plant family Aizoaceae, native to the winter-rainfall regions of South Africa and southern Namibia. Each plant is built from pairs of highly fused leaves that swell into tiny cones, buttons, spheres or bilobed bodies rarely more than a couple of centimetres tall, and every summer the plant retreats into dormancy beneath a dry, papery sheath. Affectionately known to growers as cone plants, button plants or dumpling plants (or simply Conos), the genus is a favourite among collectors of miniature mesembs for its enormous diversity of shape, marking and flower colour packed into such small plants.
Description
A single Conophytum "head" consists of one pair of leaves fused almost completely into a solid body, joined at the base and opening only through a small fissure or a pair of short lobes at the top. Bodies range from near-perfect spheres and flat-topped buttons to elongated cones and distinctly two-lobed (bilobed) shapes. Surfaces may be smooth and glassy, softly velvety, or patterned with dots, dashes and translucent windows; colours span grey-green, blue-green, bronze and reddish tones, often intensifying in strong light.
Most species are highly clumping, slowly building up dense cushions or mats of many heads over years. Flowers emerge from the apical fissure in autumn and are surprisingly large for the plant, in whites, yellows, oranges, pinks and magentas; many are day-flowering, while a good number of the smaller-flowered species open at night and are sweetly scented.
The genus's defining habit is its seasonal sheathing. As the plant enters summer dormancy the current year's body dries to a papery skin that wraps and protects the new body developing inside. When cooler weather and moisture return, the fresh head pushes out through the old sheath — a natural rhythm that governs how the plants are watered in cultivation.
Distribution and habitat
Conophytum is centred on the arid winter-rainfall zone of the western Cape and Namaqualand in South Africa, extending into southern Namibia. Many species are extreme habitat specialists, growing in rock crevices, on quartz gravel patches, or wedged into shaded cracks on cliff faces where they receive fog, dew and light seasonal rain but little summer water. This narrow specialisation means some species are restricted to a single hill or outcrop, and the genus includes a number of rare and threatened plants; wild-collected material should always be avoided in favour of nursery-propagated stock.
Notable species
- Conophytum bilobum — a larger, distinctly bilobed species with paired lobes and yellow flowers; a good beginner's Conophytum.
- Conophytum obcordellum — flat-topped button-like heads with fine dotted markings and fragrant night-opening flowers.
- Conophytum calculus — near-spherical, smooth grey-green "pebble" bodies; slow, tidy and much sought after.
- Conophytum pageae — small heart-shaped tops with a characteristic lip-like fissure.
- Conophytum ectypum — tiny patterned buttons forming neat clumps, popular with collectors of miniatures.
- Conophytum wettsteinii — forms large domed cushions, with day-opening magenta to pale-pink flowers.
Cultivation
The single most important thing to understand about Conophytum is that it is a winter grower: it is active and thirsty through autumn, winter and early spring, and dormant through the heat of summer. Getting the watering rhythm right is the whole game.
Through the growing season (roughly autumn to spring) water thoroughly when the mix has dried, letting the plants plump up and flower. As days lengthen and warm in late spring the plants naturally sheath and go dormant — at this point withhold water almost entirely, giving only the occasional light misting during the hottest months to keep roots from dying back completely. Resume normal watering once the weather cools and the new heads begin to show. See Watering for general technique.
Grow Conophytum in a very free-draining, mostly mineral mix in a shallow pot, as the root systems are fine and compact. They appreciate bright light with protection from harsh midday summer sun, which can scorch dormant bodies; good airflow helps prevent rot. Keep them cool and dry in dormancy and protect from hard frost. Because the plants are small and shallow-rooted, they are typically repotted infrequently, best done at the start of the growing season.
Propagation
Conophytum is readily grown from seed, which is the standard way to produce large numbers and to raise the many species and forms. Seed is sown onto a mineral surface at the start of the cool growing season and kept lightly humid; seedlings are tiny and slow but establish well.
Established clumps can also be increased by division: a clump is lifted and pulled or cut apart into smaller groups of heads, ideally at the beginning of the growing season so the divisions root quickly. See Propagation — offsets and Propagation — cuttings for related technique.
Hobby and cultivar notes
Conophytum is a collector's genus above all. The huge natural variation in body shape, surface pattern and flower colour means many species are grown as numbered field forms, and enthusiasts often assemble broad collections of these miniatures in a single tray. A handful of named selections and unusual forms circulate in the hobby — variegates and especially compact or heavily marked clones among them — but most plants are grown and traded as species or locality forms rather than formal cultivars. Their small size, tidy clumping habit and reliable autumn flowering make them ideal for windowsills, small greenhouses and shelf collections where space is limited.
Common problems
- Summer rot — the classic killer, caused by watering dormant plants; keep them dry and airy through the heat and only mist lightly if bodies shrivel severely.
- Failure to sheath / stalling — usually a watering-rhythm problem; align water with the winter-growing cycle rather than the calendar of summer-growing succulents.
- Etiolation — too little light makes bodies stretch, pale and lose their compact shape and markings.
- Pests — mealybugs (white fluff among the heads and roots) and, in dry stagnant air, spider mites are the usual offenders. See Pests and diseases.
See also
- Aizoaceae — the ice-plant family
- Lithops — the related "living stones", another popular dwarf mesemb
- Watering · Soil and potting mix · Repotting · Propagation — seed · Propagation — offsets