Daisies. Collection of white daisy flowers (family: Compositae). Each flower is actually a cluster of tiny individual flowers, or florets. The white petals are sterile ray florets. The yellow florets are fertile, those in the outer ring maturing earliest to expose pollenbearing anthers to insects. The yellow florets are arranged in two sets of interlocking spirals, corresponding to the Fibonacci mathematical series of numbers. Fibonacci spirals are also seen in pine cones and pineapple fruit.