Oreocereus doelzianus
| Light | Bright light to full sun; benefits from strong light to develop dense bristles |
|---|---|
| Water | Moderate in the growing season; keep dry and cool in winter |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Best above freezing; tolerates cool, dry winter rest |
| Propagation | Seed; also offsets and stem cuttings |
| Toxicity | Non-toxic to cats and dogs |
Oreocereus doelzianus is a columnar cactus from the mountains of central Peru, notable for the woolly, bristly cephalium-like crown it develops at flowering size and for its vivid red, tubular, zygomorphic (bilaterally symmetrical) flowers. Once placed in its own genus as Morawetzia doelziana and also known as Borzicactus doelzianus, it is today treated as a member of the Andean genus Oreocereus, the "old man of the mountains" cacti.
Description
Oreocereus doelzianus forms clustering, upright to sprawling stems that branch from the base, each stem several centimetres thick and ribbed, with areoles bearing stiff spines. Compared with some of its wool-draped relatives it is only modestly hairy along the stems, but as a plant reaches maturity the flowering zone near the stem tips develops a dense mass of bristles and wool — a terminal, cephalium-like crown from which the blooms emerge.
The flowers are the species' great attraction: rich red to carmine, tubular and distinctly zygomorphic, held more or less horizontally out of the bristly crown. This slightly lopsided, tube-shaped form is typical of flowers adapted for hummingbird pollination, a common strategy among Andean cacti. Fruits are small and rounded, ripening after flowering.
Distribution and habitat
The species is native to central Peru, where it grows at high elevation in the Andes among rocks and open, well-drained mountain slopes. Like other Oreocereus, it endures a cool, bright, and often harsh montane climate: intense sunlight, wide swings between day and night temperatures, and a pronounced dry season. The bristles and wool that characterise the genus are thought to help shield the plants from strong ultraviolet light and buffer temperature extremes at altitude.
Cultivation
Oreocereus doelzianus is a rewarding grower that appreciates conditions echoing its mountain home. Give it the brightest light you can — full sun in most climates — as strong light encourages tighter growth and denser bristles. Plant it in a very free-draining, mostly mineral mix, and water moderately through the warm growing season, always letting the mix dry between waterings.
Through winter, keep the plant dry and cool. A cold, dry rest not only suits its highland constitution but also helps to initiate flowering in mature plants. As with most columnar cacti, the enemy is standing moisture around the roots, so err on the side of underwatering and ensure excellent drainage. See Watering and Repotting for general technique.
Propagation
The species can be raised from seed, sown on a warm, mineral surface and kept lightly humid until the seedlings establish — see Propagation — seed. Because it clusters and branches from the base, it is also readily increased vegetatively: rooted offsets or stem cuttings can be taken, left to callus for several days, then set in a gritty mix to root.
Common problems
- Rot — the usual cause of loss, almost always from overwatering or a poorly draining mix, especially during the cool months; keep the plant dry in winter.
- Etiolation — too little light produces thin, pale, weakly bristled growth and discourages flowering.
- Pests — mealybugs (white fluff hiding in the wool and areoles) and red spider mites (fine webbing and bronzed skin) are the most likely visitors; see Pests and diseases.
See also
- Oreocereus — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — cuttings · Propagation — offsets · Repotting