Weberbauerocereus
Weberbauerocereus is a genus of tall, columnar cacti native to the arid western slopes and valleys of Peru. The plants are branching or tree-like columns, heavily armed with dense, bristly spination, and they carry funnel-shaped flowers that open in the evening and through the night — a form closely allied to Haageocereus and, in several species, apparently adapted for pollination by bats.
Description
Weberbauerocereus are large, ribbed columnar cacti that branch from the base or form a short trunk with erect arms, in some species reaching several metres tall in habitat. The stems are green to grey-green, divided into numerous low ribs and clothed in crowded areoles that bear many fine, needle-like and bristly spines — often so dense that the spination partly obscures the stem surface. Spine colour ranges from pale golden through honey-brown to grey, and old plants can take on a shaggy, weathered look.
The flowers are borne near the stem tips and are broadly funnel-shaped, opening from late evening into the night and sometimes lingering into the early morning (nocturnal to crepuscular). Blooms are typically whitish, cream, pink or dull red, with a scaly, somewhat spiny or bristly floral tube. The night-blooming habit and pale, wide-mouthed flowers of some species are consistent with bat pollination, though the long-lasting flowers are also visited by other pollinators, including hummingbirds by day. Fruits are fleshy and spiny.
Distribution
The genus is essentially endemic to Peru, growing on rocky slopes, dry valleys and desert margins along the western Andes, often in areas that receive little rainfall but some coastal moisture or fog. Plants tend to root in mineral, gritty ground with sharp drainage, and are well adapted to strong sun and long dry spells.
Notable species
- Weberbauerocereus weberbaueri — the type species, a tall branching column with dense golden to brownish bristly spines and nocturnal flowers.
- Weberbauerocereus rauhii — a robust, heavily spined columnar species popular with collectors.
- Weberbauerocereus johnsonii — a Peruvian species grown for its dense spination and columnar habit.
The circumscription of Weberbauerocereus has shifted over time, and it is closely related to — and has at times overlapped in classification with — Haageocereus; some plants once placed here are treated under that genus, and vice versa.
Cultivation
These are rewarding, sun-loving columnar cacti for the collector. Grow them in a very free-draining, mostly mineral mix in a deep pot that allows the strong root system room to develop. Give them the brightest position available — full sun suits them well and encourages tight, well-coloured spination; plants grown too dark become soft, pale and etiolated.
Water generously through the warm growing season once the soil has dried, then keep the plant dry and cool through winter to prevent rot and toughen the stems. Protect from hard frost; like most desert columnars they tolerate cool nights but resent prolonged cold and wet. See Watering and Repotting for general technique, and Pests and diseases for routine care.
Hobby and cultivar notes
Weberbauerocereus is grown chiefly as a species genus rather than for named cultivars, valued for its handsome dense spination and imposing columnar form. The genus features in intergeneric hybrids with related South American columnars, notably Haageocereus. Because mature plants flower only at night and often when large, blooms are a bonus rather than the main draw in a collection.
Propagation
Fresh seed germinates readily on a warm, mineral surface kept humid — see Propagation — seed. Branches and stem sections can also be rooted as cuttings: allow the cut surface to callus well before setting it into dry, gritty mix. See also Grafting for speeding up young or slow material.
See also
- Haageocereus — the closely allied genus
- Weberbauerocereus weberbaueri · Weberbauerocereus rauhii
- Grafting · Soil and potting mix · Watering · Propagation — seed · Propagation — cuttings