Silver Torch Cactus
Cleistocactus strausii

Family: Cactaceae

Columnar cactus that branches out from the base and can reach 10’ tall. Plants are covered in clusters of dense, hairlike white spines and a few stiffer, brown spines. The white, hairlike spines serve to protect the plant from the sun. Tubular red or pinkish red flowers appear in summer, followed by small, pear-shaped to spherical, red fruits.

Plant in full to part sun. Make sure that the plant you are growing has been acclimated to sun—many nursery-grown plants have been grown in shady, greenhouse conditions and may need to be slowly acclimated to sun. Low water when established, about once a month in summer, and probably no water in winter. Hardy to about 25°F, though older plants may tolerate colder temperatures. Small young plants should be protected from frost.

Flowers are pollinated by hummingbirds. Fruits are eaten by various birds.

The etymology of the genus name comes from the Greek term “kleistos”, “ which means “closed” and is attributed to the characteristic of its flowers scarcely opening. The species, strausii, is named after L. Strauss, a German merchant and cactus enthusiast who was co-founder of the German Cactus Society. The genus Cleistocactus has about 20 species native to mountainous areas of South America (Peru, Uruguay, Bolivia and Argentina).

Native to mountainous regions of Argentina and Bolivia, at 5000-10,000’.

Photo of mature plant in Bolivia by Martin Lowry, iNaturalist