Chamaelobivia
Chamaelobivia (also written ×Chamaelobivia) is a horticultural name for hybrids between the peanut cactus, Chamaecereus (Chamaecereus silvestrii), and various species of Lobivia. Both parent genera are now generally folded into Echinopsis, so these plants are, strictly speaking, Echinopsis hybrids — but the old cross-name has stuck in the hobby because it neatly describes what the plants are: small, freely clumping cacti that keep the peanut cactus's easy, offsetting habit while carrying the much larger, more brilliantly coloured flowers of their Lobivia parents.
What they are
The peanut cactus is a beloved beginner's plant — a sprawling mass of short, finger-like stems that offsets endlessly and produces bright red-orange flowers. On its own its blooms are relatively modest. Breeders crossed it with Lobivia, a group famous for outsized, satiny flowers in a huge range of colours, to combine the best of both: the compact, clustering, undemanding growth of Chamaecereus with showier, larger blooms. The result is the group loosely gathered under the name Chamaelobivia.
Named hobby lines exist (plants sold under cultivar-style names such as 'Rose Quartz' and similar), but much of what circulates is simply passed hand to hand as unnamed Chamaelobivia seedlings. Because both parents are so closely related, the crosses are fertile and easy, and growers have raised many generations of them.
Appearance
Most Chamaelobivia hybrids sit between their parents in habit. They form low clumps of short, ribbed, spiny stems — usually stouter and a little more upright than the true peanut cactus, but still freely offsetting into a cushion or mound. Flowers are the main attraction: broad, funnel-shaped and often large relative to the plant, appearing in spring and early summer in shades of red, orange, pink, yellow, salmon and bicolours, depending on the Lobivia parentage. A well-grown clump can carry many blooms at once.
Cultivation
These hybrids are among the easiest flowering cacti and are excellent for beginners. Grow them in a fast-draining, mostly mineral mix in plenty of light — good light encourages compact growth and heavy flowering. Water generously during the warm growing season once the soil has dried, then keep the plants cool and completely dry through winter. That cold, dry winter rest is the single most important trigger for a strong flush of spring flowers; plants kept warm and watered year-round tend to grow lush but bloom poorly. See Watering and Repotting for general technique.
Unlike the peanut cactus, which is notoriously prone to mealybugs, Chamaelobivia hybrids are generally noted as being more resistant to them — though it is still worth checking among the crowded stems at the base of a clump now and then.
Propagation
Propagation could not be simpler. A detached stem segment or offset roots easily when set on dry, gritty soil — the same method used for the peanut cactus, though the hybrids' offsets tend to cling a little more firmly than the parent's famously fragile stems. See Propagation — offsets and Propagation — cuttings. New colour forms are raised from seed, since seedlings from a cross will vary and the best are then multiplied vegetatively.
See also
- Chamaecereus · Lobivia · Echinopsis — the parent genera
- Propagation — offsets · Propagation — cuttings · Soil and potting mix · Watering