Escobaria vivipara ssp. bisbeeana
Escobaria vivipara bisbeeana is from southern New Mexico and Arizona. These plants came from near Vail, AZ and have been very cold hardy in our garden. They can get quite large around the size of a softball and always offset. They have taken -22F and seem unphased like all the spiny star. These tolerate high heat and summer monsoons as well as long periods of drought. Have not been disapointed with this species.
Try in your garden at own risk.