Tephrocactus articularus Pine Cone Cactus. Native to western Argentina, also known as the Spruce Cone Cholla. Like is on the dry side, well drained medium, full sun. In the home you will grow in a south facing window kept away from cold temps. In the summer they enjoy being outside in the Missouri summers. The spines may cause irritation if ingested by animals otherwise it is a non-toxic cactus.
 
Plants and pots may vary in sizes from the photos.  These are available at the greenhouse if you are local and want to visit.