Looks at the simple patterns that underlie the myriad diversity of form in plants and flowers. Despite apparent complexity most leaf patterns and flowers are variations on three basic patterns, which are seen in vegetative and flowering primordia. Professor Paul Green of Stanford University explains how he thinks these pattern-generating mechanisms are controlled. Professor Brian Goodwin then uses time-lapse photography and computer animation to show how his mathematical model of pattern formation reproduces the patterns observed in the growth of a giant algae.