Acanthocereus tetragonus (L.) Hummelinck

Code

ACTPE

Life form

Succulent

Biological cycle

Perennial

Habitat

Terrestrial

Overall description

Acanthocereus tetragonus is a cactus with branching succulent stems up to 4 m high. The stems are dark green, the young have 6 to 8 flat angles very marked, the adults 3 to 5 angles with slightly undulating edge. They are armed with light gray spines, arranged in a star with 6 or 7 radial spines and a longer central. Initially erect, the plant becomes climbing by branching by joints at 3 or more angles, forming thick thickets, impenetrable. White, reddish flower inside and with long red silks, 14-20 cm long funnel-shaped.  Edible fruit, oblong, bright-red when ripe, 5 to 7 cm long and 4 cm in diameter, spiny with black seeds in the pulp.

Nouvelle-Calédonie : La première phase de développement à partir de graines est lente, nécessitant plus de 8 mois pour atteindre une taille comprise entre 0,5 et 1 m. La floraison a lieu en début de saison des pluies.

New Caledonia: The first phase of development from seed is slow, requiring more than 8 months to reach a size between 0.5 and 1 m. Flowering occurs at the beginning of the rainy season.

Acanthocereua tetragonus is a perennial species. It has the ability to multiply by cuttings and seeds. It is also propagated by layering (rooting of branches in contact with the ground). Any fragment of plant, torn or cut, is likely to grow up. The seeds are also dispersed by the birds.

New Caledonia: This dry area plant shows a preference for sandy soils in coastal areas.

Origin

Acanthocereus tetragonus is native to Central America

Worldwide distribution

It was probably introduced in New Caledonia at Bouraké at the time of the rum company (19th century) as an ornamental plant.

Local harmfulness

New Caledonia: Acanthocereus tetragonus is currently only present and invasive in the Bouraké peninsula where it forms dense colonies of more than 2 m high almost impenetrable except for deer. Its presence is very problematic in deer farms where its spines migrate deeply into the flesh of animals rendering it unfit for consumption.

 

Local control

New Caledonia: The mechanical destruction of Acanthocereus tetragonus with heavy equipment (bulldozers or hydraulic shovels) is effective on adult cacti to uproot plants, crush them to promote dehydration and then wind them up and destroy them. fire. This first work should be followed by crossed subsoiling, followed by the passage of toothed tools to recover the maximum of fragments of the plant that should also be burned. The soil is then covered with a high density seeded pasture. These mechanical interventions are unfortunately often unsustainable with the rapid emergence of vegetative regrowth even on cut fragments.
The combination of mechanical treatment and chemical treatment is even more effective here. The regrowths of the year can be controlled by spraying in full or targeted depending on the situation with the combination of two active ingredients (triclopyr + picloram).
A biocontrol agent is available, the Hypogeococcus festerianus mealybug, which is specifically subservient to the cacti of the Cereanea subfamily to which Acanthocereus belongs. An attempt has been made in New Caledonia, but the insect has not been able to form a sustainable colony for the time being (Brinon, 2007, South Province).

 

Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Acanthocereus%2520tetragonus