Pseudanthium

A pseudanthium (Greek for "false flower") or flower head is a special type of inflorescence, in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The individual flowers of a pseudanthium commonly are called florets. The real flowers (the florets) are generally small and often greatly reduced, but the pseudanthium itself can sometimes be quite large (as in the heads of some varieties of sunflower).