Echinopsis pasacana This is a high-altitude cactus from the dry altiplano of the Andes of northern Argentina, and is closely related to E. terscheckii. The little branched, columnar stems, 30cm (1ft) in diameter, have more than 20 ribs, numerous soft spines, and hairs. The bell- to funnel-shaped flowers, 10cm (4in) across, in summer, are greenish or red outside, with white petals inside.
Cultivation Needs well-drained, deep, sandy soil, with a little rain, mostly in summer. It should tolerate winter cold, provided that it is dry.
Height to 3m (10ft); spread to 60cm (2ft). USZ 10–11, surviving -1°C (30°F) of overnight frost. Tolerant of summer drought.