Cereus aethiops is a shrubby, erect, more or less columnar cactus, sometimes prostrate, usually much branched from the base, to 2 m high, 1.5 m wide, with blue waxy coating on young stems and peculiar black spines. It is one of the few true Cereus which will flower when small (on 50 cm tall plants ), the night-blooming flowers are fragrant, white to pale pink, to 20 cm long. Central spines: 1 to 4, a little stouter than the radials, ascending, black, to 20 mm long. Radial spines: 7-12, grey with dark tips or black, at least at bases and tips, to 10 mm long. The most identifying feature is their remarkable ability to live smoothly in places where there is a lot of drought. They are columnar-like with stems that have sharp spines, pronounced ribs and large flowers.
