Light
Bright Indirect Light
Thrives in bright, indirect sunlight; protect from intense, scorching afternoon sun to prevent sunburn.
Reference image 
Reference image Cereus rostratus
Beaked Columnar Cactus
Overview
Cereus rostratus is a relatively rare, climbing or semi-shrubby columnar cactus belonging to the family Cactaceae. Native to the dry, coastal shrublands of the Caribbean islands, this species is appreciated by collectors for its slender ribbed stems and spectacular, nocturnal white flowers 1.
Classification and Naming
Classified under the genus Cereus, the specific epithet 'rostratus' means 'beaked' in Latin, referring to the characteristic beak-like shape of its flower buds or developing fruits. It is documented in historical botanical databases and maintains its unique position among Caribbean cacti 2.
Natural Distribution and Habitat
This species is native to the Caribbean, specifically found across the Windward and Leeward Islands, including the Virgin Islands, Anguilla, and Bonaire. It thrives in dry, rocky, limestone-rich coastal scrublands, where it often climbs over other vegetation or drapes down rocky cliffs 1.
Appearance
The stems are slender, typically featuring 3 to 5 distinct ribs, colored light green to grayish-green. The areoles bear short, sharp spines. Its nocturnal flowers are large, funnel-shaped, and creamy white. They open late in the evening and wither by mid-morning, adapted for pollination by nocturnal moths 2.
Cultivation Care
Cereus rostratus requires extremely well-draining, gritty soil to prevent root rot. It thrives in bright, filtered sunlight and enjoys warm temperatures. Watering should be deep but infrequent, allowing the potting substrate to dry out entirely between sessions 1.
Common Cultivation Mistakes
The most prevalent mistake is overwatering, particularly in heavy clay soils that retain moisture. Cold, damp winter drafts combined with wet roots can rapidly cause irreversible stem rot and fungal diseases 2.
References
Watering
10-25 Days
Water only when the substrate is completely dry. Keep nearly bone-dry during winter months.
Soil
Well-draining, sandy and pumice-enriched cactus soil mix
Requires an airy, highly porous mix enriched with coarse sand, pumice, and perlite.
Safety
Pet Friendly
Non-toxic, but the sharp spines pose a physical hazard to curious pets and children.
Difficulty
Moderate
Moderate. It is easy to care for as long as you avoid overwatering and protect it from frost.
Native Habitat
Caribbean, Leeward and Windward Islands, Northern South America
It originates from the tropical dry forests and coastal limestone terraces of the Caribbean archipelago. The species is highly adapted to salty sea breezes, rocky substrates, and prolonged periods of drought typical of these islands.
Frequently Asked Questions
Can Cereus rostratus be grown indoors?
Yes, it can be grown successfully indoors in pots placed near bright south or west-facing windows.
How often should I water it?
Water about every 10 days in summer (only when dry) and very sparingly, about once a month, during winter.
What kind of soil does it prefer?
It prefers highly porous, fast-draining cactus soil enriched with plenty of pumice, perlite, and coarse sand.
When does Cereus rostratus bloom?
Mature plants produce large, white nocturnal flowers that open during the summer nights.
How fast does it grow?
It has a moderate growth rate for a columnar cactus, putting out new growth during summer with optimal light.
Is it toxic to pets?
It is non-toxic chemically, but its sharp spines pose a physical risk of injury to curious pets.
Does it need direct sunlight?
It prefers bright, filtered sunlight. Harsh, direct midday summer sun can cause sunburn on the stems.
What winter temperature can it tolerate?
It should be kept at a minimum of 10°C (50°F) and must be strictly protected from frost.
When should I repot it?
Repot every 2-3 years in early spring, or when the root system has completely filled the current pot.
What causes mushy stems?
Soft or mushy stems are usually a sign of root rot due to overwatering. Stop watering immediately.