Melocactus is a genus of especially aesthetically interesting cacti, distinguishable by their odd cephalium that protrudes from the top. The cephalium, which is a bristly collection of aureoles, is designed to produce flowers and fruit and can grow up to 3 feet tall in some cases. Cephaliums are red or white and form small pink flowers inside their mass, and their fruits are waxy and shaped like tubes. Because of their appearance, Melocactus are popular cacti in cultivation. They are native to places with high temperatures and cannot tolerate frost: in the wild, they grow in various parts of the Caribbean, South America (especially Brazil), and Mexico.