Homalocephala

Homalocephala parryi (syn. Echinocactus parryi), commonly known as Parry's Eagle Claw, is a slow-growing, solitary, globose cactus highly prized among collectors for its formidable, curved, and heavy spine armor. It is adapted to extreme desert conditions and is considered one of the most challenging cacti to maintain in cultivation .

Homalocephala polycephala (syn. Echinocactus polycephalus), commonly known as the Many-headed Barrel Cactus, is a slow-growing, heavily spined clumping cactus in the family Cactaceae . It is renowned for its extreme drought tolerance.

Homalocephala texensis, commonly known as the Horse Crippler or Devil's Head cactus, is a robust, globose cactus species belonging to the family Cactaceae . It is infamous for its incredibly stiff, heavy spines that can easily puncture the hooves of livestock.