Silver torch cactus is a pretty cactus native to the high mountains of Bolivia and Argentina. Its slender, erect, grey-green columns can reach a height of 10 ft, but are usually only about 2.5 in across. The columns are formed from around 25 ribs and are densely covered with areoles, supporting four yellow-brown spines up to 2 in long and 20 shorter white radials. Older cactuses, over 1.5 ft tall, produce deep red, burgundy, flowers in late summer. The 3 in long cylindrical flowers protrude horizontally from the columns. In common with other cacti in the genus Cleistocactus, the flowers hardly open, with only the style and stamens protruding.