Cleistocactus ritteri

Cleistocactus ritteri is a species of Cleistocactus found in Bolivia.

Description
Cleistocactus ritteri grows as a shrub with more or less upright, bright green shoots that are branched at the base and reaches heights of up to 1 meter with a diameter of 2 to 3 centimeters. There are 12 to 16 ribs. The brown areoles on it later turn white. The 5 yellowish central spines are up to 10 millimeters long. The up to 30 fine radial spines are white.

The tubular, greenish-yellow to lemon-yellow flowers are slightly downward-pointing and barely curved. They are up to 4 centimeters long. The spherical, yellow fruits reach a diameter of up to 1.5 centimeters.

Distribution
Cleistocactus ritteri is found in the Bolivian department of La Paz in the Yungas at altitudes of 1000 to 1100 meters.

The first description was made in 1959 by Curt Backeberg. A nomenclature synonym is Cephalocleistocactus ritteri (Backeb.) Backeb. (1962).

In the IUCN Red List of Threatened Species, the species is listed as "Least Concern (LC)". H. listed as not endangered.