Melocactus is easily recognised by its rounded, ribbed body and the distinctive cephalium that develops once the plant reaches maturity. This crown-like structure is made of dense wool and bristles and produces small flowers and fruits from its surface. Native to tropical and subtropical regions of the Americas, Melocactus species vary in colour, size and spine form, but all have a distinctive appearance unlike most other cacti. Their unusual transition into the cephalium-producing stage makes them especially fascinating to experienced collectors.