Stems have 3 to 5 ribs, typically thin, with stout spines. The pretty white funnel-shaped flowers are night-opening, 12–25 cm long and 6–12 cm in diameter.
Acanthocereus tetragonus, commonly known as Barbed-wire Cactus because of its spikes, chaco, nun-tsusuy, or órgano, is the most widespread of the genus and the largest, ranging from 2-7 meters tall.
The name was first used by George Engelmann in 1863, although he did not describe its characters, leaving it to Alwin Berger in 1905 to define it as a subsection of Cereus. In 1909, Nathaniel Britton and Joseph Rose elevated Acanthocereus to a genus.Dendrocereus Britton & Rose and Monvillea Britton & Rose have been brought into synonymy.