is the more widespread of the two species of button cactus, ranging from the vicinity of Del Rio in Texas, across to central New Mexico and (less commonly) in far southeast Arizona. Plants are round in cross-section, sometimes slightly flatter on top, and between 1 and 2 inches in diameter. There are no central spines, only radial, numbering 20 to 35 per areole, densely overlapping but not completely obscuring the green stem. Spines are white or pale grey in color.
Spines towards the top of the stem are more upwards-pointing on mature plants, surrounding a woolly patch, from where small numbers of tiny pink flowers appear in springtime; they have around a dozen rounded, fringed petals, a group of pink or yellowish stamens and a white stigma. Flowers only rise slightly above the spine tips. Fruits are thin, bright red cylinders, appearing between April and June.