Stenocereus beneckei (2019)

By Pat Mahon (January 2019)

Quite seldom do I ever offer an opinion as undisputed fact: Stenocereus beneckei is the most beautiful Ceroid species that exists, hands down. Endemic to south-central Mexico, this species is renowned for its columnar body covered in dense white bloom (farina), sporting highly contrasted brown spines. How many white-bodied cacti are there out there? Who cares, this is the best one!

If one is lucky enough to find this species available, don’t hesitate to add it to your collection. If the striking beauty isn’t enough, the ease of culture is also appealing. Although the white bloom on the body is highly delicate and rubs off easily, the cactus itself is durable and tough.

An overwhelmingly small fraction of cacti enjoy the presence of humidity, and this is one that will flourish in our soggy summers. As long as S. beneckei is in a well-drained substrate, it enjoys watering during the growing season if it can dry out. In fact, if acclimated in full sun and given adequate watering and weak fertilizer, this species can grow quickly. Be sure to avoid touching and watering on the powdery bloom, as it will rub off and does not regenerate.

Propagation of this species can be done yearly by cuttings. Cut the cactus a few inches above the top of the substrate and allow the base to callous. After healing, it can be planted in pumice or other fast-draining substrate and watered lightly when roots appear.

Active growth of the mother plant is seen in the form of a branch or several branches developing from one of the tuberculate areoles. Winter rest is easily done by withholding water and giving plenty of bright sun. Only give a very tiny amount of water to sustain the body if it begins to retract in size. Amazingly, it should hold up without an issue indoors in a bright window.

Avoid cold temperatures with this species, especially when watered, as it is susceptible to fungal pathogens. Stems are 4 to 7 centimeters wide and can be 1 to 2 meters or more in height. Because of the thin trunk, the stems will often bend and bow if not supported.

Blooming Stenocereus beneckei may prove a challenge unless it is grown in a greenhouse. It should bloom in the winter, requiring minimal water and high amounts of light. The night-blooming flowers can last 24 hours. The funnel-form flowers may be pollinated in situ by bats or birds that visit. Flowers are produced at the areoles, in which the pedicel (stem of a solitary flower) may enlarge or inadvertently damage the area.

If you aren’t satisfied with a pure white, spiny Ceroid, fret not, as there is a very popular spineless form! The spineless species is one of the most unusual and almost artificial-looking cacti available, often displaying spineless, bright maroon or red areoles.

From experience, the spineless form seems harder to grow. It is often propagated and sold as unrooted scions (top part of grafts). For the beginner and even experienced grower, this spineless form can be challenging to root, so I would advise purchasing established plants, if possible.

Stenocereus beneckei belongs to a genus of very large columnar cacti, many included and segregated from Cereus. The genus name Stenocereus is an amalgamation of the Ancient Greek “steno” or “narrow” and Latin “cereus” or “wax,” alluding to the narrow, ribbed, wax candlelike body.

The species beneckei was named after A. Benecke, a succulent and cacti trader from Birkenwerder, Germany. It seems this species was first known and described in the first half of the 1800s. Benecke was mentioned in an 1899 publication to have sold cacti to Kew Gardens.

This species hails from the state of Guerrero, Mexico. It is described to have grown in red lava rock along the Rio Balsas. Unfortunately, its distribution is not well defined, even in the species description.

Sources:
Die Kakteen 1. IX C III, Stenocereus beneckei – Hans Krainz
Llifle Encylopedia of Succulents – http://www.llifle.com/Encyclopedia/CACTI/Family /Cactaceae/7444/Stenocereus_beneckei_f._iner mis