Light
Bright Indirect Light
Prefers bright, filtered light or partial shade; harsh direct midday sun can bleach or burn the stems.
Reference image Acanthocereus macdougallii
MacDougall's Barbed Wire Cactus
Overview
Acanthocereus macdougallii is a scrambling, succulent subshrub or shrub belonging to the family Cactaceae. Known for its arching or climbing branches, it often relies on surrounding vegetation or rocky substrates for physical support in its native environment.
Taxonomy and Naming
The species epithet honors the prolific botanical collector Thomas MacDougall 1. The genus name Acanthocereus combines the Greek word 'akantha' (spine) with 'cereus' (wax taper/candle), referencing the spiny, ribbed, column-like stems typical of these cacti 1.
Distribution and Habitat
Native to southern and western Mexico, including regions like Oaxaca, Chiapas, Guerrero, and Michoacán, this species thrives in seasonally dry tropical biomes 2. It is commonly found in deciduous forests, rocky outcrops, and limestone hillsides, often growing under the light shade of sparse tree canopies 2.
Appearance
This cactus produces slender, green to grayish-green stems with 3 to 4 distinct ribs. The margins of the ribs bear aeroles armed with stiff, brownish-gray spines. The flowers are large, nocturnal, funnel-shaped, and pristine white, adapted for pollination by moths and bats.
Cultivation
In cultivation, it requires a very porous, grit-rich potting medium to prevent water retention. It prefers bright, indirect or filtered sunlight over intense, direct midday sun. Water thoroughly during the active growing season only when the soil has completely dried out.
Common Cultivation Mistakes
Overwatering is the most common pitfall, quickly leading to root and stem rot. Placing the plant in heavy, clay-rich soil or exposing it to freezing winter temperatures will also cause severe decline or death.
References
Watering
10-25 Days
Water thoroughly in summer once soil is dry; reduce drastically in winter to about once a month.
Soil
Well-draining, sandy and pumice-rich cactus soil
Highly porous cactus mix amended with coarse sand, pumice, and perlite for rapid drainage.
Safety
Pet Friendly
Armed with sharp spines. Keep out of reach of pets and children, and handle with thick gardening gloves.
Difficulty
Moderate
Moderate. Easy to maintain if watering is kept in check and the plant is protected from frost.
Native Habitat
Mexico
Native to the seasonally dry tropical forests and rocky limestone slopes of southern and western Mexico, particularly throughout Oaxaca, Guerrero, and Chiapas.
Frequently Asked Questions
Is Acanthocereus macdougallii suitable for indoor care?
Yes, it can be grown indoors near bright windows. However, due to its climbing habit, it will eventually require support or a trellis and adequate space.
How often should this cactus be watered?
Water thoroughly when the soil is completely dry, about every 10 days in summer. In winter, reduce watering significantly to once every 20-25 days.
Is it toxic to pets?
This cactus is not known to be chemically toxic to pets; however, its sharp spines pose a physical injury hazard to curious cats and dogs.
What kind of soil mix should be used?
A highly porous, fast-draining cactus and succulent mix containing plenty of pumice, lava rock, and coarse sand is ideal.
When and how does it bloom?
When mature and given sufficient light, it produces large, fragrant white flowers that open at night, typically during the summer months. Flowers last only one night.
What is its growth rate?
It has a moderate to fast growth rate compared to many other cacti. Under warm, well-watered summer conditions, its stems can elongate rapidly.
Is it frost tolerant?
No, it is sensitive to frost. It should be overwintered in a dry, sheltered location where temperatures stay above 10°C (50°F).
Why are the stems turning yellow?
Yellowing stems are usually a sign of root rot from overwatering, or sunburn caused by sudden exposure to intense, direct midday sunlight.
How is it propagated?
It is easily propagated by stem cuttings. Let the cut end dry and callus for a few days before planting it in a well-draining soil mix.
How often should it be repotted?
Repot young plants every 2 years, and mature ones in spring only when the root system becomes pot-bound and crowds the container.