Leucostele rivieri (Echinopsis atacamensis)Growing primarily in the desert and dry shrubland of Bolivia and Argentina, Leucostele rivierei (Leucostele atacamensis subsp. atacamensis) produces thick columnar stems which are usually unbranched. Bright green stems are covered in yellow brown spines, which grow in between long white hairs. WATERING Water when 100% of the soil has dried out, during the active growing season between late summer through to early spring. Water sparingly during the