Echinocereus (Cactaceae) The genus Echinocereus consists of about 50 species of cactuses, natives of Mexico and southwestern USA. Many survive freezing if they are kept dry in winter. Echinocereus engelmannii This usually clump-forming cactus has long spines and purplish red to magenta or lavender flowers, 9cm (3½in) long and wide, in spring. It is wild in northwest Mexico, California, Utah, and Arizona, growing on stony slopes in the desert. The stem has a diameter of around 9cm (3½in). Cultivation Needs sandy rocky soil. Water infrequently, mostly in spring. Height to 15cm (6in); spread to 30cm (1ft). USZ 9–11, surviving -6.5°C (20°F) of overnight frost. Tolerant of summer drought. |