Cephalium

Cephalium is a, frequently brightly coloured, structure of wool and bristle at the growing tip of certain cacti. It is most commonly found on cacti of the genus Melocactus and can take a number of colours, forms and shapes. The cephalium will only begin growing after a cactus has reached a certain size or age. Once flowering begins the flower buds...
Found on http://en.wikipedia.org/wiki/Cephalium

Cephalium

The head-like stem-end of condensed cacti, bearing the flowers and fruits.
Found on http://www.gardenology.org/wiki/Glossary_of_Gardening_Terms
No exact match found