Fibonacci series in biology: two branches of "Sequoiadendron giganteum", a cone of "Pinus strobus" and a "pineapple". Each object shows left- and right handed helices, the count of which is a member of the Fibonacci sequence. The ratio of high-slope versus low-slope helix counts approximates to the golden ratio: (3/2, 5/3, 8/5, 13/8).