Fir cones
Spiral patterns in fir cones. (Copyright by, and with the permission of, R Knott, University of Surrey, www.ee.surrey.ac.uk/Personal/R.Knott/Fibonacci/fibnat.html).
A fir cone seen from below:
The same with 8 green parastichies and 13 red parastichies
picked out:
Jonathan Swinton 9/02/2001