Cleistocactus is a genus of flowering plants in the cactus family Cactaceae, native to mountainous areas - to 3,000 m (9,843 ft) - of Peru, Uruguay, Bolivia and Argentina.
Slender, columnar cacti with dense spines and tubular flowers in shades of red, pink, or orange. Flowers often remain partly closed. Best grown in full sun with well-drained soil. Drought-tolerant, protect from frost.