Haageocereus
Haageocereus is a genus of columnar — and in some species sprawling or prostrate — cacti native to the coastal deserts and lower Andean slopes of Peru and northern Chile. The genus is best known among growers for its dense, often golden, honey or reddish spination, which can wrap the stems so thickly that the green body almost disappears, and for its nocturnal, funnel-shaped flowers.
Description
Members of Haageocereus are ribbed cacti with cylindrical stems that may grow upright, lean, clamber or trail along the ground depending on the species. Many branch from the base to form clumps, while others remain more solitary and treelike. The ribs are low and numerous, carrying closely spaced areoles from which radiate slender spines. It is this spination that gives the genus its ornamental appeal: colours range from pale straw and gold through amber and honey to rich rust and reddish tones, and the density varies from a light comb to a near-solid sheath.
The flowers open at night and are funnel-shaped, borne near the stem tips. They are typically white to pale pink or greenish, and — as with many night-blooming cacti — may stay open into the following morning. Pollinated flowers give way to fleshy fruit containing small black seeds. As with most desert columnar cacti, growth is steady rather than fast, and mature plants develop a distinctly weathered, sculptural character.
Distribution
Haageocereus is a South American genus centred on Peru, where it is a characteristic component of the coastal lomas fog-desert and the arid western foothills of the Andes, extending south into northern Chile. In habitat these cacti endure long rainless periods and draw much of their moisture from coastal fog, growing in gritty, mineral, sharply drained ground on slopes and rocky flats under intense light.
Notable species
- Haageocereus pseudomelanostele — a widespread and variable Peruvian species, often the one first encountered in collections.
- Haageocereus acranthus — an upright columnar species from the Peruvian coast.
- Haageocereus decumbens — noted for its sprawling, decumbent stems that trail across the ground.
- Haageocereus versicolor — prized for spination that shifts through bands of colour along the stem.
- Haageocereus multangularis — a many-ribbed columnar species of the coastal desert.
Because the genus is variable and has been reclassified repeatedly, plants are sometimes still traded under older names such as Peruvocereus, and boundaries between species are not always sharp.
Cultivation
Haageocereus are rewarding container plants for the grower who can give them strong light and a lean, mineral diet. Grow them in a very free-draining, mostly mineral mix and provide the brightest position available — full sun encourages the tight, well-coloured spination the genus is grown for, whereas shade produces thin, pale, etiolated growth. See Watering for general technique: water generously during the warm growing season once the soil has dried, then reduce sharply and keep the plants dry and cool through winter to prevent rot and improve cold tolerance. They are not frost-hardy and should be kept above freezing.
Repot occasionally into fresh gritty mix as clumps outgrow their containers; handle the spiny stems with folded paper or thick gloves. See Repotting and Pests and diseases for more. Overwatering, poor drainage and insufficient light are the main causes of trouble in cultivation.
Propagation
Haageocereus can be raised from seed, which germinates readily on a warm, mineral surface kept humid until the seedlings establish. Clumping and branching species are also easily increased from stem cuttings: sever a stem or branch, allow the cut to callus and dry for several days, then set it on gritty mix and water only lightly until roots form. Vigorous rootstock-grown or offsetting plants may also be propagated from offsets where they occur.
Hobby and cultivar notes
In cultivation Haageocereus is valued above all for its spination, and growers tend to select forms with the most intense gold, honey or red colouring and the densest cover. The genus is not as heavily bred into named cultivars as some ornamental cacti, so plants are more often distributed as attractive wild forms and colour variants than as formal cultivars. Colour and spine density can shift noticeably with light levels, so a plant's best appearance is usually achieved under strong sun.
See also
- Soil and potting mix · Watering · Repotting
- Propagation — seed · Propagation — cuttings · Propagation — offsets
- Pests and diseases