Capitulum

A capitulum (plural capitula), also called a flower head, is a dense inflorescence of many small, stalkless flowers (florets) crowded together on a common flattened or domed base and surrounded by protective bracts, so that the whole head is easily mistaken for a single flower. It is the defining flower structure of the daisy and sunflower group, where an outer ring of showy strap-shaped florets often surrounds a central mass of tiny tubular florets.