Selenicereus anthonyanus
| Light | Bright, indirect light; a few hours of gentle morning sun is fine, but shield from harsh midday sun |
|---|---|
| Water | Regularly through the warm months, letting the top of the mix dry between waterings; ease off in winter |
| Soil | Loose, airy, humus-rich epiphyte mix (see Soil and potting mix) |
| Temperature | Warmth-loving; keep above about 10 °C, USDA zones 10–11 |
| Propagation | Stem cuttings (very easy); also seed |
| Toxicity | Generally regarded as non-toxic to cats and dogs |
Selenicereus anthonyanus is an epiphytic, jungle-dwelling cactus from southern Mexico, grown almost everywhere as an easy trailing houseplant. Its long, flattened stems are cut into deep, rounded lobes down each side, giving them the look of a backbone or a row of teeth — hence the common names fishbone cactus and zig-zag cactus. Like many night-blooming cacti it produces large, short-lived nocturnal flowers, and it is still sometimes sold under its old name Cryptocereus anthonyanus.
Description
Selenicereus anthonyanus is a scrambling, climbing epiphyte whose primary stems are cylindrical and firm, while the familiar flattened side branches hang and trail. These flattened stems are strap-like and green, deeply notched along both edges into alternating rounded lobes so that the midrib stands out like a spine flanked by ribs. Tiny areoles sit in the notches, sometimes carrying a few soft bristles rather than true spines. Grown in a hanging pot, the stems cascade freely and can reach well over a metre in length.
The flowers are the classic Selenicereus spectacle: large and showy, opening after dark and fading by morning. They are typically creamy white to pale yellow within, with narrow, reddish-purple outer segments, and are strongly fragrant. Because each bloom lasts only a single night, flowering is a brief event to be caught rather than a long display, and mature, well-established plants flower most reliably.
Distribution and habitat
The species is native to the humid forests of southern Mexico, where it grows as an epiphyte — perched on tree trunks and branches rather than rooted in the ground. In this habitat its roots run through pockets of leaf litter and mossy bark, it receives dappled light beneath the canopy, and it enjoys warmth and steady humidity with good air movement. Understanding this origin explains its care: it is a shade-tolerant, moisture-appreciating cactus, quite unlike the desert globes many people picture.
Cultivation
Selenicereus anthonyanus is one of the more forgiving cacti and an excellent beginner's epiphyte. Grow it in a loose, airy, humus-rich mix — an orchid or aroid-style blend with bark and perlite suits it well — in a hanging pot or basket where the stems can trail. Give it bright, indirect light; a little gentle morning sun deepens the colour, but strong direct sun will scorch and yellow the stems.
Unlike desert cacti, it likes to be watered fairly regularly through spring and summer, allowing the top of the mix to dry before watering again, and it appreciates warmth and moderate humidity. Cut watering back in winter and keep it above about 10 °C. A cooler, drier winter rest, followed by a return to warmth and feeding in spring, encourages the plant to set flower buds. See Watering and Repotting for general technique.
Propagation
Propagation is very easy from stem cuttings. Take a healthy length of the flattened stem, let the cut end callous over for a few days, then lay or pot it into a moist, airy mix; roots form readily at the areoles in the notches. Sections potted several to a container fill out quickly into a full plant. The species can also be raised from seed, though cuttings are so simple and true to the parent that this is the usual route. See Propagation — cuttings for a full walkthrough.
Common problems
- Rot — from a soggy, poorly draining mix or standing water; stems turn mushy and translucent. Use an open mix and empty any drip trays.
- Sunburn — too much direct sun bleaches and scars the stems; move to brighter shade.
- Shy flowering — usually a young plant, or one that never gets a cooler, drier winter rest to trigger budding.
- Pests — mealybugs (white fluff in the areoles) and scale are the most common; see Pests and diseases.
See also
- Selenicereus — the genus overview
- Epiphyllum — the related "orchid cacti", grown much the same way
- Propagation — cuttings · Soil and potting mix · Watering · Repotting · Pests and diseases