Selenicereus wercklei

Native Home and Botanical History

Selenicereus wercklei is a Costa Rican climbing and epiphytic cactus of wet tropical forest. Its flexible, largely spineless stems grow over or from trees instead of forming a self-supporting desert trunk, and its nocturnal flowers follow the night-flowering pattern common in the genus.

The species was first described as Cereus wercklei and has also appeared as Selenicereus inermis subsp. wercklei. These are older names for the same Costa Rican cactus, which is distinct from the dragon-fruit species S. undatus. International movement is covered by CITES Appendix II, as it is for almost all cacti.

Care for epiphytic roots and trailing growth

Light, temperature and humidity: Selenicereus wercklei grows best in bright, filtered light with soft morning or late-day sun. Its slender green stems scorch and dehydrate faster than the thicker stems of dragon fruit, so avoid a sudden move into intense midday sun. Maintain warm, frost-free conditions with moderate to higher humidity and continual air movement.

Watering and root care: Water when the mix has partly dried during active growth. Use a coarse epiphytic cactus substrate that drains immediately yet retains a little moisture around the fine roots. In winter, keep the plant bright and reduce moisture modestly without allowing the root system and thin shoots to remain bone dry for long. A cool wet base is the main condition to avoid.

Support, feeding and repotting: Let the stems hang freely or guide them over a support that does not compress them. Feed lightly while fresh sections are extending, and remove only dead or damaged growth. Repot with minimal disturbance after roots have filled the container. Healthy stem pieces can be propagated after the cut surface dries briefly, then placed in a warm, airy rooting mix rather than enclosed in stagnant humidity.

Solving Problems with Selenicereus wercklei

The slender shoots of Selenicereus wercklei hold less water than thick dragon-fruit stems. Wrinkling above a dry root zone with firm roots calls for complete rehydration and drainage. Glassy-looking tissue at the base is a sign of decay when the mix is still wet. Remove the affected section and root sound growth again in an airy epiphytic mix.

Its naturally narrow, nearly spineless shoots should not be labelled as stretched by low light merely because they are thin. New growth that becomes unusually weak, pale and widely spaced still usually means insufficient light. Move it gradually into brighter filtered conditions because abrupt exposure to stronger sun can bleach or cork the exposed side.

Scale and mealybugs hide at stem joints, old flower sites and supports. Confirm raised covers or waxy insects, isolate the plant and repeat treatment through new growth. Dry stable scars do not need to be cut out. Any soft patch that enlarges should be kept dry and removed back to firm tissue.

Keep Selenicereus wercklei away from children and pets

• Keep this plant away from children, cats and dogs.
• Its effects after chewing or swallowing are unclear, and plant material can still cause an upset stomach.
• Contact a veterinarian or medical professional if symptoms develop or do not settle.

Where does the name Selenicereus wercklei come from?

Selenicereus combines Selene, the Greek moon goddess, with Cereus, a cactus name associated with a wax taper or candle. The species epithet wercklei honours the German botanist Karl Wercklé.

Nathaniel Lord Britton and Joseph Nelson Rose established the genus Selenicereus in 1909 in Contributions from the United States National Herbarium, volume 12, page 429.

Frédéric Albert Constantin Weber first described it as Cereus wercklei in 1902 in Bulletin du Muséum d’Histoire Naturelle (Paris), volume 8, page 460. Nathaniel Lord Britton and Joseph Nelson Rose later placed it in Selenicereus as Selenicereus wercklei in 1920 in The Cactaceae, volume 2, page 208.