This variety is listed as endangered. Photos on this page were taken in the Waterman Mountains, Arizona. There are always 8 ribs, which may be straight or twisted into a slight spiral.
Spines are white, gray, purple, and pink, and are flat on top or nearly round.
Anomalous plant with unusually broad, flat, dark spines. This slow-growing cactus requires limestone gravel. Pink flowers in March-April. Fruit is a dry brown oval capsule hidden in white fuzz. Most plants at this locality are old, but there are a few young ones, including several buds on older plants.