Acanthocereus is a genus of cacti in the family Cactaceae, order Caryophyllales, native to the tropical Americas. The genus comprises shrubby plants with long arching or climbing stems that can reach several meters in height, making them distinctive among New World cacti.
Stems typically bear 3 to 5 prominent ribs armed with stout spines. The plants begin as erect shrubs but mature branches often spread, arch, or trail, giving established plants a scrambling, sometimes vine-like habit. The large, white, funnel-shaped flowers are among the showiest in the cactus family, measuring 12–25 cm long and 6–12 cm in diameter. They are strictly nocturnal, opening at night and pollinated by moths or bats. Fruits are spherical to pear-shaped, red or green, and contain broadly oval, shiny black seeds up to 4.8 mm across.
The genus ranges from the southern tip of Florida and coastal Texas south through Mexico, Central America, the Caribbean islands, Colombia, and Venezuela. The most widespread and largest member, Acanthocereus tetragonus (Barbed-wire Cactus), reaches 2–7 m tall and defines the genus's typical growth form.
Acanthocereus was first named by George Engelmann in 1863, formally characterized as a subsection of Cereus by Alwin Berger in 1905, and raised to full genus rank by Nathaniel Britton and Joseph Nelson Rose in 1909. The name combines the Greek acantha (spine) with the Latin cereus (candle), a reference shared with closely related columnar cacti.
Etymology
The generic name Acanthocereus combines the Greek άκανθα (acantha), meaning "spine," with the Latin cereus, meaning "candle" — a reference to both the plant's prominent spines and its tall, candle-like stems. The name follows the convention used for related columnar cacti in the tribe Cereeae.
Distribution
Acanthocereus is native to the mostly tropical Americas, ranging from coastal Texas and the southern tip of Florida south through Mexico, Central America, and the Caribbean islands, reaching the northern edge of South America in Colombia and Venezuela. Within this range the genus favors tropical dry forests, scrublands, and coastal thickets.
Taxonomy Notes
The genus name was first published by George Engelmann in 1863, though without a formal description of its characters. Alwin Berger defined it in 1905 as a subsection of Cereus, and Nathaniel Britton and Joseph Nelson Rose elevated it to genus rank in 1909. Two former members — Acanthocereus brasiliensis and Acanthocereus sicariguensis — have since been transferred to the genus Strophocactus.
