Barnsley's fern is a fractal shape, discovered by Michael F. Barnsley at the Georgia Institute of Technology, that has many geometric features in common with a natural fern, most notably the appearance of frond-like forms at different scales. As in the case of real ferns, Barnsley's fern reveals smaller prominences along the edge of each frond that are miniature versions of the overall figure. Along these small prominences are still smaller protuberances, and so on. Barnsley's fern is created by the repetitive application of four relatively simple mathematical rules and is a type of fractal, introduced by Barnsley, known as an iterated function system (IFS).
1. Barnsley, Michael. Fractals Everywhere 2nd edition. San Francisco: Morgan Kaufmann, 1993.