The pediocactus genus include some of the smallest cacti in the US, growing mostly in north Arizona and Utah. Eight of the nine species are rare (pediocactus simpsonii is the exception), and most occur in very localized areas, sometimes of just a few square miles. They are known as pincushion cacti.



There are four other US pediocactus species:

Pediocactus despainii, Despain's pincushion cactus, east central Utah (San Rafael Swell)
Pediocactus knowltonii, Knowlton's miniature cactus, north New Mexico near the Colorado border, north of Farmington
Pediocactus nigrispinus, Snowball cactus, scattered locations in Oregon, Washington and Idaho
Pediocactus winkleri, Winkler's pincushion cactus, east central Utah (San Rafael Swell)