Epithelantha micromeris 'Button Cactus' SB1327
Epithelantha micromeris aka the Button Cactus is cold hardy to around -10F if you plant it in a crevice or crack. It has taken -17F for us but is not reliable. These really are a crevice plant and do best when grown harsh. Plants can get baseball sized but are not cold hardy at that size. Plants are also a great container plant and are as spiny as velcro. This seed is from Belen, NM however there is much confusion as to where it actually came from.