Publication: [ as: Cereus chiloensis var. zizkaanus K.Schum. 1897]
Description
Growth Habits: T. chiloensis is a fiercely spiny cactus. It develops into a shrub or small tree.
Stem: Rarely single, usually of several branches, sometimes of many, arising from near the base, starting nearly at right angles to the main trunk but soon erect, up to 8 m tall, stems 10-12.5 cm in diameter ; 10 to 17 low and broad ribs, separated by narrow intervals, divided into large tubercles even when fully mature.
Areoles/Spines: Areoles large whitish, 2 cm apart. Spines yellowish with brown tips, at least when young, greyish later; 1 to 4 centrals, porrect, often stout, 5-7 cm (or even 12 cm); 8 to 12 radials, up to 4 cm long.
Flowers: Nocturnal 14 cm. long, outer perianth-segments white but tinged with red or brown; inner perianth-segments white, acuminate.
Origin and Habitat
North-Central Valley of Chile, from Curico to Puenta Colorado.
Habitat: Chilean matorral in the upper hill-slopes that flank the higher Andes. The climate in this area is similar to that of the Southern Californian chaparral.
Cultivation and Propagation
Trichocereus chiloensis is very easy to grow and cold hardy as low as -12°C (or less). Need a fertile, well drained soil mix. Water the plants well and allow them to dry before watering again. This species seems to do better with a little more water than most cacti. In fact, its cultivation requirements are really more like ‘normal’ plants than most other cacti. During the growing season fertilize them monthly with a balanced fertilizer
Sun Exposure: Outside full sun, inside needs bright light, and some direct sun. During winter month, put them in a cool luminous place and encourage them to enter winter dormancy by withholding water and fertiliser over the winter as they will etiolate, or become thin, due to lower levels of light. They are susceptible to fungal diseases if overwatered, but are not nearly as sensitive as many other cacti, especially in warm weather. They tend characteristically towards black rotted spots unless watering is moderate and only in hot weather, if kept damp through cold periods, they will invariably suffer.
Trichocereus chiloensis produces noticeable amounts of growth each year if kept well fed and watered throughout the warmest months, particularly if it has been acclimatised to accept full sun. Once this cactus is established it can easily produce 20cm of growth every year.
Propagation:: Cutting or from seed. The seeds are quite easy to germinate and grow. Their main requirements consist of high humidity levels, free-draining soil mix, and enough water, light, and nutrition
Notes
The original name for this cactus was Trichocereus chiloensis. In 1950, Skottsberg pointed that the name was misspelled, and was changed to “chilensis” for “Chile”+“ensis”. The rules of nomenclature now, give priority to the original name, misspelling included, except if the name was changed by the original author. Thus, Friedrich & Rowley retained chiloensis when they included the genus Trichocereus into the genus Echinopsis.
This species is occasionally confused with Trichocereus litoralis.