Thelocactus tulensis subsp. matudae is a globular cactus closely related to Thelocactus tulensis subsp. buekii, but with distinctive longer tubercles, higher spine number and larger flowers. Both taxa are subspecies of the very variable polymorphic Thelocactus tulensis which comprises innumerable geographical forms linked one to each others by populations of plants with intermediate characteristics. Such variations has led to establishment of several unnecessary names for this species.