Mammillaria spinosissima cv. 'Un Pico' Crassulaceae but you can prune it

but you can prune it regularly to better show off the roots

and possibly my favorite in the genus

The leaf width is roughly in the middle of those two species

It produces elongated leaves on stiff vines from a caudex

Mammillaria spinosissima cv. 'Un Pico' Crassulaceae but you can prune itMammillaria spinosissima cv. 'Un Pico' A very distinctive form of this popular species. Most areoles have just a single straight white spine poking out. That contrasts with the normal species that is covered in countless spines. Will clump in time but normally isn't a heavy clumper. Produces lots of pink to magenta flowers in the warmer months. Takes normal cactus care. Protect from frost. You will receive a plant shown in the last image or one