Website has loads of information about the Fibonacci sequence and the Golden Number and how they occur in nature (Rabbits, cows, bees family trees, rectangles and shell spirals.
Introduces the fibonacci sequence and how it appears in nature with pine cones, artichokes, flowers, etc.
Vihart actually show how she counts the number of spirals using a marker.
This vid discusses how the fibonacci sequence occurs in plants and introduces the number phi, which is the limit of the ratio between two consecutive fibonacci.
Discusses situatiions in plants where we don't have fibonacci sequences but we get something similar - Lucas numbers.Vihart also explains why these fibonacci numbers occur in nature (sort of).
Website talks about the relationship between the Fibonacci sequence and plants found in Nature. Also contains a cool little applet where one can enter how much of a turn a plant would make before growing a new leaf.