The probably best known example for fractals is the romanesco broccoli. Each of the small sprouts are a downscaled, self similar copy of the whole broccoli. Additionally the sprouts are arranged in a logarithmic spiral.
Often we can find Fibonacci numbers in fruits and seed pods.
To get an idea how simple the rules are that create these shapes, let’s examine the input needed for a computer to generate a romanesco broccoli:
rotate z, -110
That is it.
Further Reading & Sources
Fractal Food – Fourmilab
Fractal Analysis & Characterization of Tropical Fruits – Paper, University of Singapore
Who would expect that this is how an MRI-scan cutting through a banana looks like:
and some more MRI’s of fruits – can you guess what is what?