Haageocereus fascicularis grows as a shrub with ascending to upright, gray-green shoots that branch from the base and reach a length of 0.5 to 1 meter with diameters of 4 to 7 cm (1.6 to 2.8 in).

The white, strongly scented flowers reach a length of 7 to 8.5 cm (2.8 to 3.3 in).

Its pericarpel and flower tube are covered with hairs and reddish scales.

The first description as Cereus fascicularis was made in 1833 by Franz Julius Ferdinand Meyen.

The Cactus Family By Edward F. Anderson, Wilhelm Barthlott, Roger Brown