Light
Bright Indirect Light
Bright indirect light or filtered sun; shield from intense midday solar radiation.
Reference image 
Reference image Acanthocereus rosei
Rose's Acanthocereus
Overview
Acanthocereus rosei is a scrambling, tuberous-rooted succulent shrub belonging to the family Cactaceae. Known for its nocturnal blooming habit and slender branches, it is a fascinating species for specialized collectors 1.
Taxonomy and Naming
Named in honor of the prominent American botanist Joseph Nelson Rose, this species has been historically placed under the genus Peniocereus as Peniocereus rosei. Recent phylogenetic studies have integrated it into the expanded genus Acanthocereus 2.
Distribution and Habitat
This species is native to western and northwestern Mexico, spanning regions like Sinaloa, Nayarit, Jalisco, Colima, and Guerrero. It typically inhabits dry deciduous forests and arid shrublands, growing under the protection of larger shrubs 1.
Appearance
It features thin, green to grayish-green segmented stems with 3 to 5 prominent ribs. The areoles carry short, needle-like spines. Below the surface, it forms a large, starchy tuberous root that helps the plant survive prolonged droughts. The funnel-shaped white flowers open at night and are strongly scented 1.
Cultivation
In cultivation, it thrives in bright filtered light or partial shade rather than harsh direct sunlight. A highly porous, mineral-rich potting mix is essential. Water thoroughly only when the substrate has completely dried out, and keep the plant dry during its winter dormancy.
Common Mistakes
Overwatering is the primary cause of failure, leading to the rapid decay of the underground tuber. Insufficient light results in weak, thin, and elongated stems. Keeping the plant in cold, damp soil during winter is highly detrimental.
Bibliography
References
Watering
10-30 Days
Water only after the substrate has dried out completely; keep nearly dry in winter.
Soil
Well-draining cactus mix blended with pumice and coarse sand
Highly porous, fast-draining mineral mix containing ample pumice or perlite.
Safety
Pet Friendly
Features small, sharp spines. Non-toxic to pets, but keep out of reach to avoid physical injury.
Difficulty
Moderate
Moderate care level due to strict watering requirements and tuber rot susceptibility.
Native Habitat
Mexico
Native to the dry deciduous scrublands and arid coastal plains of western and northwestern Mexico, where it grows semi-protected under canopy shade.
Frequently Asked Questions
Can Acanthocereus rosei be grown indoors?
Yes, it can be grown indoors, but you must provide a support stake for its scrambling stems and place it in a location with plenty of bright, filtered light.
How often should I water it?
Water roughly every 10 days in summer once the soil is completely dry. In winter, reduce watering to once a month or less.
How do I prevent the tuberous roots from rotting?
Prevent root rot by using a highly porous, well-draining cactus mix and ensuring that water never accumulates in the saucer.
What type of soil should I use?
A specialized cactus and succulent mix containing pumice, lava rock, coarse sand, and a small amount of peat is ideal.
Does Acanthocereus rosei bloom?
Yes, mature plants produce large, white, fragrant, funnel-shaped flowers that open at night during the summer.
Is it toxic to pets?
It is non-toxic, but the spines can cause mechanical injury to pets' mouths and paws, so keep it out of reach.
What is its cold tolerance in winter?
It can tolerate temperatures down to 5°C for brief periods, provided the soil is kept dry. Protect it from frost.
Is it a fast grower?
Tuber growth is slow, but its slender climbing stems can elongate relatively quickly during the growing season under optimal warmth and light.
What causes the stems to thin and stretch (etiolation)?
This indicates the plant is not receiving enough light. You should move it to a brighter location with filtered sunlight.
Can it be propagated from cuttings?
Yes, stem cuttings can be taken, allowed to callouse for a few days, and then rooted easily in a well-drained substrate.