Melocactus (melon cactus) is a genus of cactus with about 30-40 species. They are native to the Caribbean, western Mexico through Central America to northern South America, with some species along the Andes down to southern Peru, and a concentration of species in northeastern Brazil. The first species was named by Carl Linnaeus in 1753, as Cactus melocactus. When the genus was separated from Cactus, the pre-Linnaean name Melocactus was used.