Cleistocactus ritteri

Cleistocactus ritteri grows as a shrub with more or less upright, bright green shoots that are branched at the base and reaches heights of 1 to 2 meter with a diameter of 2 to 3 centimeters. There are 12 to 14 ribs. The brown areoles on it later turn white and 5 mm apart. The 5 yellowish central spines are up to 10 millimeters long. The up to 30 fine radial spines are white and 6–8mm long. The tubular, greenish-yellow to lemon-yellow flowers are slightly downward-pointing and barely curved that blooms from the areoles near the apex of the stems. They are up to 3–4 centimeters long and 5 mm wide. The spherical, green to yellow fruits reach a diameter of up to 1.5 centimeters. Seeds are black pyriform and 0.8 mm long.

Cleistocactus ritteri is found beneath trees and shrubs in loamy soil of the Bolivian department of La Paz in the Yungas at altitudes of 2700 to 3000 meters.