Cleistocactus strausii

The light green shoots reach a diameter of up to 8 cm (3.1 in) and are completely covered by dense, white spines.

There are 25 to 30 ribs and are densely covered with areoles, supporting four yellow-brown spines up to 4 cm (1.5 in) long and 20 shorter white radials.

They are deep red to burgundy and grow up to 6 cm (2.5 in) long cylindrical flowers protrude horizontally and radially from the stem of the cactus.The flower-tube is very densely covered with silky hairs.

In common with other cacti in the genus Cleistocactus, the flowers hardly open, with only the style and stamens protruding.

Rooting of this new cutting usually occurs within 3-8 weeks, therefore it is usually better to propagate silver torch cactus via seed.

This cactus prefers free draining soils, strong sunlight, but not high temperatures; in fact it can withstand hard frosts down to −10 °C (14 °F).

In the United Kingdom, this plant is usually grown under glass, and has gained the Royal Horticultural Society's Award of Garden Merit.