Originating from Bolivia, the Cleistocactus winteri, this furry cactus better known as the monkey tail cactus, finds its home in the Florida province, located in the Santa Cruz department. This region is notable for its topographic and climatic diversity, providing a conducive environment for the development of a variety of life forms, including this unique species of cactus. The natural habitat of the monkey tail cactus is characterized by altitudes ranging from approximately 1300 to 1500 meters (4265 to 4921 feet) above sea level, where it grows on exposed, rocky, and steep slopes, rooting in crevices and cracks and draping its hanging branches over the rocks, often above the forest canopy.
The taxonomic history of Cleistocactus winteri is complex, marked by several name changes since its first description. Originally described as Winteria aureispina by Friedrich Ritter in 1962, the name had to be changed due to the reclassification of the genus, and the preexistence of Cleistocactus aureispinus Frič in 1928. Over the years, it has been known by various taxonomic synonyms, including Winterocereus aureispinus, Hildewintera aureispina, Loxanthocereus aureispinus, Borzicactus aureispinus, and finally, as Cleistocactus winteri by David Richard Hunt in 1988, with the name Cleistocactus aureispinus considered illegal due to its prior existence. The subspecies colademononis was initially published as a unique species, Hildewintera colademononis in 2003, before being renamed by Hunt in 2005 as Cleistocactus winteri subsp. colademono.
The genus name Cleistocactus derives from the Greek “kleistos“, meaning closed, a reference to the almost closed nature of the flowers of this cactus species. The specific epithet “winteri” honors Hildegarda Winter, sister of Friedrich Ritter. The subspecies colademononis, in turn, is a visual tribute to its unique appearance resembling a monkey’s tail, “cola de mono” in Spanish.
Cleistocactus winteri is a columnar cactus, initially erect and later pendant, and can reach up to 2.5 meters (8.2 feet) in length. Its cylindrical stems, light green in color and with a diameter ranging between 2 to 7 cm (0.79 to 2.76 inches), are completely covered by fine, hair-like spines, giving the plant a soft and attractive appearance. The flowers of this species are zygomorphic, almost horizontal in relation to the stem, with a bright red color, and measure approximately 7-8 cm (2.76-3.15 inches) in length. The fruits, reddish in color, are more or less spherical, measuring 8-12 mm (0.31-0.47 inches) in diameter, and open longitudinally upon reaching maturity. The seeds, black and slightly curved, measure between 1.1-1.4 mm (0.043-0.055 inches) in length, and germinate easily.
Within the Cleistocactus winteri species, there are two subspecies with distinct characteristics. The subspecies Cleistocactus winteri subsp. colademononis, the true monkey tail cactus, is characterized by its long and soft spines that do not prick and resemble white hairs. Its flowers, of an intense red, are particularly decorative.
On the other hand, the subspecies Cleistocactus winteri subsp. winteri, known as the golden rat tail cactus, shares the columnar form and pendant growth habit, although more compact, but differs in specific morphological details, such as the color and size of the spines, which are shorter, firmer, thicker, and yellow in color, as well as the flowers, which are slightly smaller and acquire shades of salmon.
There is also a cristata form of Cleistocactus winteri. This form presents abnormal growth, resulting in stems that expand in a wavy and flattened manner, resembling a crest or sea wave. This mutation gives the plant a unique and highly ornamental appearance, making it a highlight in any collection. However, extra care is needed to maintain the mutation, especially regarding propagation, which should be carried out by cuttings.
The monkey tail cactus, with its unique and exotic shape, offers a range of possibilities in landscaping, transforming common spaces into interesting scenarios. Its epilithic (lithophytic) nature, that is, its ability to grow on rocky surfaces, makes it an ideal choice for rock gardens and xeriscaping projects. Its adaptation to arid environments and its pendant appearance allow it to stand out in compositions with stones, adding texture and movement to the design, especially on rocky walls, where it can drape its stems.
One of the most popular applications of Cleistocactus winteri in landscaping is in pots and hanging baskets, where its long, pendant stems can be dramatically displayed, close to eye level. This approach adds verticality and depth to outdoor and indoor spaces. On balconies, patios, or home entrances, hanging baskets with the monkey tail cactus create focal points of great beauty. For the same reasons, this species is highly sought after for low-maintenance vertical gardens, especially those more exposed and with low availability of irrigation.
For cactus and succulent enthusiasts, Cleistocactus winteri is a valuable addition to collections due to its peculiar shape and showy flowers. In themed gardens that explore the flora of arid or desert regions, this cactus is an indispensable addition. In mini-succulent gardens, bowls, logs, and raised planters, it brings besides the unique color and texture, the pendant element that softens the rigid and geometric edges of the containers, as well as creating contrast with other species.
Regarding light exposure, this cactus prefers to be under high luminosity, benefiting from full sun or partial shade daily (4 hours or more of direct sunlight). However, in very hot climate regions, it is preferable to provide indirect or filtered sunlight during the hottest hours to prevent possible burns on the stems. In terms of temperature, Cleistocactus winteri adapts well to a wide variation, being ideal to maintain between 41°F and 86°F (5°C and 30°C). For regions with cold winters, it is recommended to protect the plant from extreme cold. Good air circulation is also crucial to prevent fungal diseases, especially in enclosed spaces or during winter.
Watering should be adjusted according to the season: water regularly during spring, summer, and autumn, allowing the soil to dry completely between waterings, and minimally in winter, keeping the substrate almost dry. When watering, prefer to water deeply, until excess water exits the drainage hole, rather than watering little by little. It is crucial to use a well-draining substrate to avoid moisture accumulation, recommending substrates specific for cacti, added with a bit of fibrous material, such as coconut fiber or composted pine bark. Do not use saucers under pots.
Fertilization should be done with products specific for cacti and succulents, following the manufacturer’s instructions to avoid overdosing. Avoid using organic fertilizers, except for the liquid ones, well diluted, which can be an interesting complement. Repot the monkey tail cactus every two years to renew the substrate and stimulate the growth of new healthy roots. Repotting helps to keep the substrate airy and draining, in addition to replenishing organic matter that has degraded over time.
The monkey tail cactus propagates both by seeds and cuttings. Sowing, ideal at the beginning of spring, involves spreading the seeds superficially on a specific potting mix for seeds, like Carolina Soil, and keeping them moist in an area of indirect light. Using transparent pots, which can be closed, helps to maintain constant moisture and temperature. Propagation by cuttings, carried out at the end of spring or beginning of summer, requires the cuttings to form a callus before being planted in draining substrate, maintaining slight moisture until rooting. Before cutting the cuttings, remember to mark the correct position with a tape, avoiding planting the cuttings upside down later. Although less common, Cleistocactus winteri can also produce shoots at the base, which can be carefully removed for propagation.
