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 triglochidiatus This usually clump-forming cactus has long spines and bright red flowers, around 7cm (3in) long and wide, in spring. It is wild in the mountains of California, Nevada, and Arizona, growing on dry rocky slopes. The stem has a diameter of around 9cm (3½in). Cultivation Needs sandy rocky soil. Water infrequently, mostly in spring. Height to 20cm (8in); spread to 30cm (1ft). USZ 9–11, surviving -6.5°C (20°F) of overnight frost. Tolerant of summer drought. |