Cleistocactus samaipatanus

Scientific Name: Cleistocactus samaipatanus (Cárdenas) D.R. Hunt
Synonym: Akersia roseiflora, Bolivicereus brevicaulis, Bolivicereus croceus, Bolivicereus rufus, Bolivicereus samaipatanus, Borzicactus roseiflorus, Borzicactus samaipatanus
Family: Cactaceae

Recommended Temperature Zone:
USDA: 9b-10

Frost Tolerance: Hardy to 25° F (-3°C)

Heat Tolerance: Avoid reflected light, they do better with some afternoon shade

Sun Exposure: Full sun to light shade

Origin: Bolivia, Peru

Growth Habits: Succulent, grow in group of trailing or erect slender columns, 3 to 5 feet long (0.9 to 1.5 m), one to 2 inches in diameter (2.5-5 cm); 14 to 17 ribs; 13-40 stiff golden spines.

Watering Needs: Water generously during the summer, less in winter

Propagation: Easy to propagate from cuttings or seeds

This Cleistocactus is possibly one of the best landscaping cactus. Its slender columns 1-2 inches in diameter are covered with short golden spines. It branches readily and each stems lasts for several years, growing increasingly woody, before it should be removed to encourage young growth.
The plants described as Akersia roseiflora by Buining, have stems around 2 inches thick (5 cm), 16-17 low ribs, and lilac pink flowers.

Blooming Habits:
The Cleistocactus samaipatanus blossoms freely in cultivation (the picture was taken mid-April in Phoenix). The brilliant red to pink flowers, 1 inch in diameter (2.5 cm), 2 inches long (5 cm), don't close at night, and they last about 4 days. They come in flushes in late spring to early summer.

Culture:
The Cleistocactus is a vigorous plant, if you grow it in a container, repot it yearly with a loam based mixture, and give an occasional high potassium liquid feed.