Light
Bright Indirect Light
Requires at least 6 hours of bright indirect or filtered sunlight daily.
Reference image Cereus undiflorus
Wavy-Flowered Cereus
Overview
Cereus undiflorus is a rare and lesser-known columnar cactus species belonging to the family Cactaceae 1. Native to the Caribbean islands, this species is characterized by its upright green stems and nocturnal white flowers with distinctive wavy-edged petals.
Taxonomy and Naming
Originally collected and documented in Cuba, this species remains classified under the genus Cereus 1. The specific epithet undiflorus refers to the undulating or wavy margins of its large, night-blooming flowers.
Distribution and Habitat
The primary native range of this species is Cuba 12. It grows within arid scrublands, coastal limestone cliffs, and dry, thin soils where drainage is exceptional and sunlight is abundant.
Appearance
It forms a branched or single columnar stem with distinct ribs. Prominent areoles along the ribs carry several spines. The flowers are large, funnel-shaped, nocturnal, and exhibit pale, delicate wavy petals designed to attract nocturnal pollinators.
Cultivation
In cultivation, Cereus undiflorus requires extremely well-draining substrates and protection from freezing temperatures during winter 2. It appreciates consistent watering during summer and total dryness in winter.
Common Cultivation Mistakes
The most frequent failures involve overwatering, using compact soil, and exposing the plant to freezing temperatures while the soil is wet, which causes root rot.
Bibliography
References
Watering
10-25 Days
Water only after the substrate is entirely dry. Keep dry in winter.
Soil
Well-draining, pumice and sandy cactus mix
Requires highly porous gritty mix with pumice, sand, and minimal organic matter.
Safety
Pet Friendly
Spines can cause physical injury. Handle with thick gloves. Non-toxic to pets.
Difficulty
Moderate
Moderately easy if overwatering is avoided and drainage is optimal.
Native Habitat
Caribbean, Cuba
This cactus is native to the Caribbean region, specifically found in the dry, rocky limestone habitats and xerophytic shrublands of Cuba.
Frequently Asked Questions
Can Cereus undiflorus grow in a pot?
Yes, it can be grown successfully in pots indoors or on patios, provided you use a highly porous cactus mix and a pot with drainage holes.
How often should it be watered?
Water about every 10 days in summer (only when dry) and reduce to once every 25-30 days or not at all during winter dormancy.
What type of soil should be used?
An open, gritty cactus mix with plenty of pumice, lava rock, coarse sand, and minimal peat moss is ideal.
Is it toxic to pets?
It is non-toxic, but the sharp spines pose a physical injury hazard to curious cats and dogs.
When does it bloom?
Mature plants bloom during the summer, producing large, white, wavy-edged flowers that open during the night.
How much sunlight does it need?
Bright, filtered sunlight is best. Protect it from extremely harsh, direct midday summer sun to prevent sunburn.
What is its growth rate?
Like many columnar cacti, it has a slow-to-moderate growth rate, gradually gaining height over several years.
What is its minimum winter temperature tolerance?
It tolerates temperatures down to 8°C (46°F). It is frost-sensitive and should be kept indoors or in a greenhouse during winter.
Why is it turning yellow and soft?
Yellowing and softening at the base indicate root and stem rot caused by overwatering. Stop watering immediately.
How can it be propagated?
It can be propagated via stem cuttings (allowing the cut to callus for a few days before planting) or from seeds.