Selenicereus anthonyanus (Alexander) D. R. Hunt
Fish Bone Cactus, Fishbone Orchid Cactus, Rick Rack Cactus, Ric Rac Orchid Cactus, Zig-Zag Cactus, St. Anthony's Rik-Rak
Selenicereus anthonyanus is a fast-growing epiphytic cactus with climbing stems. It branches in clusters at intervals along the stem. The unusual leaf-like branches are green, up to 3.3 feet (1 m) long, and 6 inches (15 cm) wide. They have up to 2 inches (5 cm) long and up to 0.5 inches (1.3 cm) wide lobes tapered towards the rounded apex.
The showy, fragrant flowers have dark violet-rose outer petals, white inner petals, yellow stamens, and a prominent white-branched pistil in the center. They are up to 4.8 inches (12 cm) long and 6 inches (15 cm) in diameter. Flowers appear in late spring and early summer and are open in the late afternoon and evening, lasting only one day.
USDA hardiness zones 10a to 11b: from 30 °F (−1.1 °C) to 45 °F (+7.2 °C).
How to Grow and Care
Perhaps the most important aspect of epiphytic cactus care is the potting soil. Experts are strongly divided on using commercial cacti or orchid mixes, but they agree that epiphytes need well-draining potting soil with lots of air space since the roots would naturally be exposed to air. If you wish to create your own mix, start with a basic formulation of 60% potting soil to 40% perlite. Other amendments are often added, including peat, orchid bark, sand, fine gravel, and leaf mold. Aim for a pH of 5.0 to 6.0, and plan to repot every 2 to 3 years if you use ingredients that eventually break down completely, such as orchid bark.
In most situations, epiphytes do not exist in the open sun, instead of receiving bright filtered light. They thrive as houseplants because of their relatively low lighting requirements. Ideally, you should provide full morning sun and shade for the rest of the day. An east-facing window with nothing blocking it can create these conditions. Light will affect the plant's willingness to bloom, though these requirements vary widely between epiphytes. Many can be coaxed into blooming by simulating short days by placing them in dark closets for 12 or more hours at a time for 4 to 6 weeks.
Learn more at Tips for Growing Epiphytic Cacti.
This cactus is native to southern Mexico.
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