Is typically a spiny plant of the Sonoran and Mojave deserts, growing in large clusters (up to 60 stems), The cactus is somewhat variable in the color, size and distribution of spines, and occurs in a number of regional varieties. Spines tend to be thickest for plants towards the west of the range, and are colored in various shades from white to dark brown, on the same plant. The longest spine (up to 3 inches) is always white. Like most hedgehog cacti, the spring flowers are very bright and colorful. They are followed by spiny, greenish fruits that turn red when ripe. Stems are upright at first but may fall to the ground with old age and grow laterally. This is one of the most common of the hedgehog cacti.