Nature Notebook – Spirals in Nature

What do fern fiddleheads, coiled millipedes, and coiled garden hoses have in common with pinecones and sunflowers? They are all spirals. The first three are called Archimedes spirals. The spiral increases at a constant rate from its start. Picture that coiled garden hose.

The pinecone and sunflower display double spirals. If you trace the lines of scales or seeds, you will see curves that move clockwise and other curves that move counterclockwise. The total of each type of curve almost always (you can never say “always” with nature) equals a number listed in the Fibonacci Sequence (see * below for a segment of the sequence). The number of opposite curves will be an adjacent Fibonacci number.

Fibonacci numbers are also seen when the numbers of leaves on plant are calculated and the arrangement of leaves around a stem is examined. Scientists theorized that these numbers represented the most efficient design for maximum sunlight for the leaves.

…and you just thought pinecones made pretty decorations.

*Fibonacci Sequence: 1, 1, 2, 3, 5, 8, 13, 21 (next number is the sum of the last two numbers and so on)