See text Armatocereus (from Latin armatus, "armed" and cereus, "pliant/soft") is a genus of mostly tree-like cacti from South America (Ecuador and Peru).

Armatocereus species are columnar cacti, bushlike or treelike, with cylindrical upright branched stems.

The narrow tubular flowers appear at night, and have a spiny ovary and floral tube and white petals (red in A. rauhii).

However, at the time, the International Code of Botanical Nomenclature required a Latin description for a genus name to be accepted, and this was not published until 1938.

[2] Classifications based on morphological characters placed Armatocereus in the subfamily Cactoideae, tribe Browningieae.