Armatocereus rauhii is a tall, branched columnar species of cactus endemic to the north of Peru on the western slopes of the Andes.

[4] Armatocereus is a tall, treelike cactus, bluish to greyish green in colour, usually with a trunk to about 1 m (3 ft) high followed by upright branches.

Depending on the subspecies, it reaches a maximum height of 6–10 m (20–33 ft), with branches 8–15 cm (3+1⁄4–6 in) thick.

The flowers are 10–15 cm (4–6 in) long, carmine or purple in colour, with black to red spines on the floral tube.

Within the country, the stated distribution of the species as a whole and of the subspecies varies by source, but centres on the regions of Amazonas, Cajamarca and Lambayeque.